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nanonano
05-03-08, 13:45
Purchased a bucket of the above new salt at the weekend and did the first mix today, thought i would post my observations.

I decided to add the salt to the RO water prior to any heating or circulation to see what the solubility was like. The water temp was 15c and within 2 minutes of adding the salt ( at 35g per litre) 90% of the salt had dissolved...very good indeed.
I then added a heater and a small circulation pump (without aeration) and brought the water temp up to 25c which took 30 minutes, at which point all the salt had dissolved and i was left with a very "clean" looking mix...again very good indeed.
I then checked the salinity and found it to be a little shy of the 35ppt that i was aiming for. It took 37.5g of salt per litre to give me a salinity of 35ppt.
Alkalinity (salifert) checked out at 2.74 meql or 8.00 dkh
Calcium (salifert) checked out at 420 mgl
Magnessium (salifert) checked out at 1470 mgl
Potassium (fauna marin) checked out at 300 mgl
Nitrate (salifert) checked out at 0.2
Phosphate (d+d Merck) checked out at 0.03

I am only a hobbyist and tests were obviously not done under lab conditions, i was also using hobbyist test kits, however due care and attention was taken in undertaking the tests and all tests were completed twice.

Observations:
The salt mixed easily and very cleanly. The tub has a tight fitting, air tight lid and the internal poly bag has a simple plastic sealing tag which is easy to secure and help keep the bag air tight.
I was disappointed with the low potassium reading (much lower than advertised) as this was one of the main reasons for purchasing this salt. I appreciate that the Potassium test being based on turbidity isn't the easiest to interpret, but having said that and allowing for the variance of the human eye, the result was still very low.
The Nitrate and Phosphate results were a little surprising.

Looks like i am going to have to continue purchasing costly Potassium additives for the near future which wasn't the plan.

Has anyone else tried and tested this salt yet?

muzzy
05-03-08, 13:50
thanks for the post

that potassium result is a bit shocking!
everything else looked ok, phos reading could be down to dirty vials, ro container not being sterile, RO itself not being great even if it showed as zero tds
in fact a small almost unreadable ammount of phosphates is fine, but 0.03 is still way higher than what id like to see

nanonano
05-03-08, 13:58
Muzzy

Yes i was rather disappointed at the potassium result.
With regards to phosphates i agree with you, as i have found that true zero phosphate in a ULNS isn't good and ive had to take steps to increase the level to 0.008 (pls bear in mind this is in the coral farm with only 2 very small fish). As much care as possible was taken with the tests, but as i sadi they were not conducted under lab conditions and hence why i wondered if anyone else had run some tests.
The RO unit is less than 12 months old, DI resin and first pre filter were changed only two weeks ago and output after DI chamber is reading 0 TDS.

muzzy
05-03-08, 14:37
how often do you clean the vials?
before doing a phos test i always use a small bottlebrish and ro water to clean the tubes, then rinse in RO and then rinse in tank water before filling to do the test!
a pain, but from what i have gathered, phosphate particles can stick to the tubes and possibly give a false high reading

KeithM
05-03-08, 14:52
potassium at 300ppm is still ok - nothing to be too concerned about IMO

muzzy
05-03-08, 14:53
people on zeo forum would beg to differ

nanonano
05-03-08, 15:04
Muzzy

Vials are cleaned with test tube brush and ro water after use and rinsed again in ro water before use.

Have just done further phosphate tests as follws:

1) using Ro water direct from ro unit ...... zero reading
2) using RO water from Ro storage container ..... zero reading

have now done a new test mix using a brand new container and brand new pump.
3) salt mix ..... 0.03 reading

i am now waiting for new mix to come up to temp so that i can adjust salinity and i will then re test Potassium.

KeithM
05-03-08, 15:06
people on zeo forum would beg to differ

They would differ about lots of things :D

IMHO, 300ppm is on the edge of being low, not something I'd be overly concerned about though. If potassium was at 200ppm then that would be pretty shocking. 300-350ppm is within the OK range 350-400ppm is in the 'spot on' range

nanonano
05-03-08, 15:07
Keith

As per Muzzy the Zeo forum have very strong views on Potassium levels and also from personal experience i have found this to be true, with levels below 350 having adverse effects in ULNS and 370 to 380 being optimum in such systems.

muzzy
05-03-08, 15:08
Muzzy

Vials are cleaned with test tube brush and ro water after use and rinsed again in ro water before use.

Have just done further phosphate tests as follws:

1) using Ro water direct from ro unit ...... zero reading
2) using RO water from Ro storage container ..... zero reading

have now done a new test mix using a brand new container and brand new pump.
3) salt mix ..... 0.03 reading

i am now waiting for new mix to come up to temp so that i can adjust salinity and i will then re test Potassium.
ok mate

not looking too good IMO

muzzy
05-03-08, 15:09
They would differ about lots of things :D

IMHO, 300ppm is on the edge of being low, not something I'd be overly concerned about though. If potassium was at 200ppm then that would be pretty shocking. 300-350ppm is within the OK range 350-400ppm is in the 'spot on' range

I prefer to be in the "spot on range" than in the "OK" range :)

nanonano
05-03-08, 15:30
spot on or ok aside, either i've messed up the test (am only human) or the info on the side of the tub.... level 410 , range 380 - 420 is adrift.

Having just looked again at the D+D website it states that the parameters are taken at sg 1.025 at 25c = 35.5ppt

is that a correct conversion?, i had always worked on:
1.025 at 25c being equal to 33.9ppt
35.5ppt at 25c being equal to 1.0262 sg

Having said all that i can't see that it would be the cause of such a difference on the Potassium test result.

KeithM
05-03-08, 15:41
did you make sure the dry salt was well mixed inside the bucket?

nanonano
05-03-08, 16:33
Rolled it around the lounge for five mins, but to be honest its tightly packed and little room to move so not sure how helpful that would have been.

nanonano
05-03-08, 16:46
Just tested second batch for Potassium

35ppt at 25c Potassium again 300 mgl

Disappointed to say the least

Stuart Bertram
06-03-08, 20:22
Guys

Before you get too carried away I think you should know that during development of this salt we had numerous samples of water from coral seas, Davids tank and salt samples tested at a number of water testing labs.

You would be amazed by the variations that we got back even from the same water at different labs and so if they get different readings how can anyone expect to get accurate results with a hobby test kit.

We did find some test kits were good and others were well out but there were variations even with the same brand.

Hammond from Tropicals and Marines also tested the salt and found the levels right on the mark.

What I am suggesting is that the results that you have achieved may be missleading.

We have such confidence in the levels that not only do we print them on the bucket we even give a range that we guarantee to hit batch to batch

pH - 8.2 - 8.4
dKH 8.7 - 9.8
calcium - 430-460
magnesium - 1300 - 1380
chloride - 1990 - 20130
potassium - 380 -420
nitrate 0
phosphate 0

You will also notice that these readings are at a salinity of 35.5 not 35 which equates to 1.025 at 25C.

Also note for nitrates and phosphates that many test kits are not designed to test pure RO water and will give a false zero reading - the only way to be sure is to pass it over DI resin to get absolute zero before mixing the salt.

Many people do not know how to use a refractometer properly and can be measuring the wrong salinity which is why we give advise on a leaflet with the salt - supplied seperately on this first batch.

Variation of Specific Gravity with Temperature

Specific gravity varies with temperature. The warmer the water, the less dense the solution becomes and therefore the lower the S.G.

When mixing up a salt solution, the pre-salted water is often at a lower temperature than the aquarium water and therefore it is helpful to know the equivalent S.G of a salt solution mixed at that lower temperature.

Example:
If we assume that the goal is to produce water with an S.G. of 1.025 at 25 OC but that the starting water has a temperature of only 18 OC.

By using the chart below we can see that for water at 18 OC we need to make a solution with a measured S.G. of 1.0268 which when warmed to an aquarium temperature of 25 OC will expand and the S.G. will fall to the correct level of 1.025.





Salinity 35.5 ppt

Temp. (°C) S.G. Calibrated at 20 OC
18 .........1.0268
19 ..........1.0264

20 ..........1.0262
21 ..........1.0260
22 ..........1.0258
23 ..........1.0256
24 ..........1.0253
25 ..........1.0250
26 ..........1.0246

Calibration of Measuring Equipment

It is important to note that equipment for measuring S.G. is calibrated to give a reading at a specific temperature and that different types of equipment are often calibrated at different temperatures. Hydrometers for example are often calibrated at 25 OC whereas refractometers are usually calibrated at 20 OC.

It is important to take this information into consideration when measuring your final specific gravity.

Calibrating a D-D ATC Refractometer.

The D-D refractometers are auto temperature compensating which actually means that once correctly calibrated they can be used to read solutions regardless of what temperature the equipment is and not that it will give the correct reading at a range of different water temperatures.
The sample of water used for testing is so small that it will soon equilibrate with the temperature of the refractometer and not the other way round.

When calibrating the refractometer it is important that the instrument and not the water sample tested is at 20 OC.

Once calibrated the instrument can be used at a range of equipment temperatures, (assumed to be the same as the room temperature) but will always give you a reading corrected to
20 OC.

From the chart opposite we see that when using a refractometer, (calibrated at 20 OC), we should be aiming for a reading in our aquarium of 1.0262 if we intend to have a S.G. in the tank of 1.025 at 25 OC.

If the aquarium is adjusted to 1.025 with a refractometer then the true specific gravity will in fact be in the order of 1.024.

All the best

Stuart

drivewayreef
06-03-08, 20:36
:confused: can you get refractometers with built in temperature guages? :thumbsup:

nanonano
06-03-08, 22:06
Stuart

Many Thanks for responding to my thread.
Firstly let me clarify that i am not "D+D or product bashing" in any way. I think my initial post was very clear in that respect.
I was going to try RBS however my confidence in D+D products lead me to wait until your salt was available. I have also over the past 12 months strongly promoted your nanocubes which i believe are the best in the market.

However having read your response i feel i now need to make a few comments.

1) You will see from a previous post that after getting a positive test result for phosphate, i then tested both the ro water exiting the ro unit and also the ro water in the reservoir both of which gave a zero test result using a D+D merck test kit. You will also see from a previous post here that i use DI resin and that it had been replenished only two weeks ago and that the TDS meter is giving a zero reading post DI chamber.

2) I was not given or offered a leaflet regarding how to use a refractometer, however i can confirm that my Aqua medic refractometer has been correctly calibrated.

3) To my knowledge the only potassium test kits available to the hobbyist are the KZ and FM ones. I use the FM test kit and got the same reading on four separate tests over two batches. which was 300ppm.

I fully agree that there are good and bad test kits and also that a brand of test kit may vary from batch to batch. However i feel that the potassium test results i was getting are not even close to your published figures, for whatever reason, and that could well be human error on my part.

So i am prepared to take my bucket of salt to a place of your choosing and have it tested in my presence for potassium and phosphate levels. I truly hope that i am proven wrong and i will be the first to make a very humble and public apology.

Best Regards
Paul

chris@bluzoo
06-03-08, 22:26
This is a very interesting thread, I am sure the FM kits are very good, I have customers who are really glad that these came out. They really know their stuff too. I know you can really rely on the D-D merck test kit.
I will be keeping a close eye on this :):)
Chris

muzzy
06-03-08, 22:35
paul, feel free to send me a water sample for testing this salt, obviously no charge as im as interested in the results as the next man

chris@bluzoo
06-03-08, 23:27
paul, feel free to send me a water sample for testing this salt, obviously no charge as im as interested in the results as the next man

Which potassium test kit do you use Muzzy :)

nanonano
07-03-08, 00:42
Muzzy
Thanks for the offer, perhaps it would be better if i sent you some of the salt as i got the impression from Stuarts post that there was an implication that the results could be affected by the way it was made up.

muzzy
07-03-08, 10:48
Which potassium test kit do you use Muzzy :)

FM as well

muzzy
07-03-08, 10:50
Muzzy
Thanks for the offer, perhaps it would be better if i sent you some of the salt as i got the impression from Stuarts post that there was an implication that the results could be affected by the way it was made up.


yeah possibly would be better. about 75g would be enough I guess
really up to you, and whether anyone thinks that me testing it will give any results to be considered worthy :whistling:

nanonano
07-03-08, 11:04
Muzzy, as to you being worthy....who knows but i would value your test results. PM me with your postal address and i will get some in the post to you.

Stuart, my offer to take my tub to a place of your choice for testing is still open.

Regards
Paul

muzzy
10-03-08, 21:14
OK my test results are in

temp 26c
SG 1.026
DKH - 8.60
Calcium - 415
Magnesium - 1410
Potassium - 360

these were Pauls results:

salinity of 35ppt.
Alkalinity (salifert) checked out at 2.74 meql or 8.00 dkh
Calcium (salifert) checked out at 420 mgl
Magnessium (salifert) checked out at 1470 mgl
Potassium (fauna marin) checked out at 300 mgl

I used exactly the same test kits, although probably different batch numbers.

all look ok to me, although not quite in line with what Paul found. This could be due to a variation in salinity/temp, different test kit batches and different eyesight!

test kits should be allowed at least a 5% +/- margin for error so I dont think these are much different to the stated ammounts on the tub, all are acceptable levels.

And the levels that stuart indicated it should be at:

dKH 8.7 - 9.8
calcium - 430-460
magnesium - 1300 - 1380
potassium - 380 -420

iain360
10-03-08, 21:30
Good thread this one, have been toying with the idea to use the D+D salt instead of the Tmc salt. What would impress me the most if the levels were hit batch after batch after batch. Anyone else using the D+D for a while now who can see consistent levels in the salt mixes?

muzzy
10-03-08, 22:00
i dont think the salt has been around long enough to draw that conclusion, and I doubt that many batches have been produced so far.
I think you may need to wait a while longer to see whether fluctuation occurs.
All salts I have used personally, different results have been found, I think that is just something we have to accept. What is unacceptable would be hugely varying test results from batch to batch, minor variances I can live with.

Take the Kent salt for example - now no longer produced, or at least in that guise.
One bucket I had, had 2200ppm magnesium, another 1500.
Another bucket had 1dkh and another 9 or 10!
I remember a major outcry in the states over the low alk kent salt and although recalled overthere, nothing was done here in the UK. That was one of the worst examples of customer care Ive seen in this hobby, one i hope not to see again

jobr
10-03-08, 22:00
Good thread this one, have been toying with the idea to use the D+D salt instead of the Tmc salt. What would impress me the most if the levels were hit batch after batch after batch. Anyone else using the D+D for a while now who can see consistent levels in the salt mixes?

TMC salt, when did they start making salt?

The readings on the D&D salt that you guys are getting seem on a par with what one would expect for the type.

muzzy
10-03-08, 22:03
TMC salt, when did they start making salt?

The readings on the D&D salt that you guys are getting seem on a par with what one would expect for the type.

dont be pedantic mr jobby, you know he means tropic marin salt :rolleyes: :D

iain360
10-03-08, 22:13
dont be pedantic mr jobby, you know he means tropic marin salt :rolleyes: :D

Took the words right out of my mouth:D

With reference to the batches, It was the continued parameters between buckets i refered too, some of my previous salt choices have been woefully lacking in consistancy, just be nice to play on a level playing field sometimes.

I have heard of some lfs having the D+D salt for a while now, testing it on their own systems, as a bit of R and D shall we say. Be interesting to find out how they have been running.

muzzy
10-03-08, 22:16
well ill let you do that research, i dont have time to phone every LFS in the country to find out how its going, let us know how you got on, expect results back by end of the week! :thumbsup:

jobr
10-03-08, 22:18
dont be pedantic mr jobby, you know he means tropic marin salt :rolleyes: :D

I thought I had missed another company introducing a salt:eek:

muzzy
10-03-08, 22:20
well i dont mind if they do, if people keep sending me salt to test i wont need to ever buy another bucket again :D

Tony B
10-03-08, 22:21
OK my test results are in

temp 26c
SG 1.026
DKH - 8.60
Calcium - 415
Magnesium - 1410
Potassium - 360

these were Pauls results:

salinity of 35ppt.
Alkalinity (salifert) checked out at 2.74 meql or 8.00 dkh
Calcium (salifert) checked out at 420 mgl
Magnessium (salifert) checked out at 1470 mgl
Potassium (fauna marin) checked out at 300 mgl

I used exactly the same test kits, although probably different batch numbers.

all look ok to me, although not quite in line with what Paul found. This could be due to a variation in salinity/temp, different test kit batches and different eyesight!

test kits should be allowed at least a 5% +/- margin for error so I dont think these are much different to the stated ammounts on the tub, all are acceptable levels.

And the levels that stuart indicated it should be at:

dKH 8.7 - 9.8
calcium - 430-460
magnesium - 1300 - 1380
potassium - 380 -420

Muzzy, what about PO4 & NO3? :)

muzzy
10-03-08, 22:24
didnt do it!
i still have some salt left, but really cant be bothered to test these.
Phosphate and nitrate will be present in any salt in anycase.

if you want me to test these ill have to do it tomorrow, been up since 4am and i really dont think ill get an accurate result with my eyes half shut!

nanonano
10-03-08, 22:24
Muzzy thanks for running those tests.

Its interesting that our Ca tests are only 1% apart, and Mg 4% difference, whats of more concern to me is the K test where we are 20% different especially when we are both using Fm test kit.
I wonder if this is an indication of just how varied individual interpretation of turbidity tests are. The dilema now is do i adjust my K level or not.
Did you do a phosphate test.
Thanks
Paul

nanonano
10-03-08, 22:28
Just seen more posts was taking me too long to type mine.
Thanks again Muzzy for taking the time to run those tests.

muzzy
10-03-08, 22:33
all part of the service.
ill give you the address to send the cheque to :D

iain360
10-03-08, 22:55
well ill let you do that research, i dont have time to phone every LFS in the country to find out how its going, let us know how you got on, expect results back by end of the week! :thumbsup:

:bookread: Best I get phoning then:D

Screwloose
11-03-08, 19:26
pretty sure Mark at Acrapora house was selling this :D

keithboylan
16-03-08, 13:24
I was reading this thread as I wanted to change my salt from Instant Ocean so it was either Reef Cryastals of D-D H2Ocean and the later won out on price for me £45 each when I bought 3 buckets I done some tests and this is the results I came up with as another reference for any body

Temperatture 23c
SG - 1.026
Ammonia - 0
Nitrite - 0
pH - 8.4
dKH -10.4
calcium - 400
magnesium - 1320
chloride - not tested
potassium - not tested
nitrate 0
phosphate 0

All tests were carried out with Salifert but for Phosphates was D-D and PH was with IKS probe

tomcoleman
26-11-08, 10:00
i'm about to buy a couple of buckets of salt - been reading up. confused on what to buy now.

sophos9
28-11-08, 09:17
D&D mate, anything else is a false economy!

ellasae
29-11-08, 22:21
D&D mate, anything else is a false economy!

agree completely,imo easily the best salt i've used.

mikef
30-11-08, 14:17
From a shop point of view, its a no brainer, D & D is the best salt we have ever used, we use it for our own systems and for our ready salted water too.

We have used this salt for approx 6 months, having now got through some 60 plus buckets in that time with no problems at all.

A plus side is we have noticed a decrease in the amount of additives we need to use since swopping onto this salt, it also mixes up very quickly and does not leave a resdue in the mixing vats

Matt G
30-11-08, 22:14
A plus side is we have noticed a decrease in the amount of additives we need to use since swopping onto this salt, it also mixes up very quickly and does not leave a resdue in the mixing vats

I am surprised at that, I have used a number of buckets now and the container is always dirty after mixing. Dirty film all around the container and a grit left in the bottom, always have to give it a good clean after. I have just changed back to Tropic Marin, first water change tonight and the water change container is a clean as a whistle and the params are also good.

sophos9
30-11-08, 22:55
There were some reports of early batches creating a brownish residue - this is due to the phosphate removal process in the factory - nothing to worry about!

ricky
08-01-09, 21:53
well i am a bit dissapointed in the h2 ocean salt...i was very happy to of found a salt of high mag so i brought a tub...
i have made a five gallon mix salanity is 1.026 heated at 25.3..done a mag test and its 1200 with saliferts kit..this was with a level spoon of mag 2...so i done a second test with a heap of mag 2 on the spoon and got a reading of 1260..still under rated to what dd specify...

steve mullin
08-01-09, 22:25
suspect test kit mate. Been using it for a year now, home, shop, everywhere:laugh: never seen Mg below 1350 and always test my salt mix.

sophos9
09-01-09, 09:20
i have made a five gallon mix salanity is 1.026

Your problem is the way you are reading your refractometer and not allowing reduction SG calibration.

1.026 is your specific gravity NOT your salinity. Please look through the eyepiece of your refractometer and check to see something that says d=20/20 or 20/20 - this is the definition of SG as per the refractometer manufacturer.

20/20 means the SG of the sample at 20 deg C divided by the density of of freshwater at 20 deg C

What was the temperature of your refractometer when you tested?

D&D recommend their salt at a SALINITY of 35.5ppt or 35.5% - achieve this then test again...

ricky
09-01-09, 16:06
sorry i mean sg...checked mag in tank and is 1350...just re checked salt mix and its now reading 1050...something wrong here...

ricky
09-01-09, 16:08
cant be test kit as the tank would be the same...i bet i have the first dodgy salt tub..lol

ricky
10-01-09, 15:09
ok guys,been out today and brought a new salifert mag kit...also took my refractometer to 2 shops had them checked against theirs...mine and theirs both matched the same so refrac is ok ..

have done test with brand new kit mag reads 1260...done test with old sali kit mag reads 1260...so this salt is under what dd recommend..this is with sg at 1.026 temp 25.

sophos9
10-01-09, 16:40
:) you would be the first ;)

First things first, forget about SG, seriously!!!

Secondly, get your salinity up to 35.5% as directed by D&D then retest...

Bradden
10-01-09, 17:12
I would also recommend giving the salt a good mix. I always roll it around a few times before using a new bucket.

ricky
10-01-09, 17:45
35.5 shows 1.026 on th refrac so im confused? please enlight..

sophos9
10-01-09, 18:33
35.5 shows 1.026 on th refrac so im confused? please enlight..

The scales are not equal and as such, are not directly comparable!

If we agree that NSW is about 35 %%, that's a density of 1.02334 g/cm3 (or if you prefer, kilogrammes per litre) at 25 C.

There are as many measures of SG as of length (inches, furlongs, metres.....measuring the same thing but in different units, so giving different numbers). And while we'd spot the difference between an inch and a furlong, the various units of SG are sufficiently similar as to be easily overlooked and confused.

So it is not possible to give advice generally about "the target SG" without also being specific about the SG measure used. Okay, now it gets boring (if not already).

SG is the density of the sample at a particular temperature, divided by (in most measures) the density of pure water at some reference temperature. If the reference temperature is about 4 C, the divisor is (close to) 1. If the reference temperature is 25 C, the divisor is 0.9970. These are both commonly used as divisors.

So, if your density at 25 C is 1.02334 g/cm3, matching "NSW", your SG meter, depending on the maker, will read 1.0233 or 1.0264. Each is the same salinity. Totally different result. It's not a question of accuracy, it's a question of which units are being used.

So what does we do ?

If you are a nutter, and have bought a meter that reads SG then you check what definition of SG is used. It will be written on the instrument.

Eg it will have engraved upon it 25/20 - ie it displays the SG of the sample at 25 C (or ATC to the same) divided by the density of pure water at 20 C.

And now you have to look up what target SG, as measured on that scale, you need. It won't be the same as everyone elses, because they are all using different scales.

If it is not written on the instrument, then the reason is simple. It's cheap and nasty. It's not written there because the manufacturer is making it impossible to interpret the results in a scientific fashion. It could read anything, and you would never ever be able to show that it was wrong because it makes no claim as to what it is reading.

Like somebody who makes tape measures, but won't tell you if it's in inches or cm, or something else. You'll never be able to prove that the number is wrong ! You may be disappointed (tho' chances are you'll never notice), but you have no grounds for complaint.

ricky
10-01-09, 19:10
i understand all this but i am going by what the refrac says...ok i have just raised the ppt to 38 which shows an sg of 1.028...now the mag in the salt mix is 1350..i had it at 35.5ppt but mag read 1260.....have calibrated the refrc so many times to get it spot on...so i am still none the wiser....hmm

ricky
10-01-09, 19:36
35.5 is not 1.025 on a refractometer..where do they get this from?

sophos9
10-01-09, 20:15
Exactly!!!! Refractometers use a deceivingly different scale (did ask you to check your refractometer for the d=20/20 or 20/20) - I explained this in a previous post...

NSW is 35% or PSU or PPT which means 35 parts per thousand. The SG of NSW IS between 1.024 and 1.026

sophos9
10-01-09, 20:19
The best thing people can do is buy a refractometer that measures salinity only!

ricky
10-01-09, 20:38
i use a dd refract on the left side it says..d2020 at the top 20c right is percent and bottom says salinity..
so what your saying then is i have to mix mine up so my sg will be 1.028...but thats to high..

ricky
10-01-09, 20:41
thanks for your patience:whistling:

ricky
10-01-09, 21:07
how do you tell if th refrac is at 20c?

sophos9
10-01-09, 21:25
i use a dd refract on the left side it says..d2020 at the top 20c right is percent and bottom says salinity..
so what your saying then is i have to mix mine up so my sg will be 1.028...but thats to high..

Basically, what this means is the that the ATC (Automatic temperature control) will adjust your sample to that of 20 deg C regardless and the SG changes with its temperature. SG fluctuates with temperature so 35ppt salinity at 25 deg C is 1.0264, 35ppt salinity at 20 deg C is about 1.025ish

thanks for your patience:whistling:

No probs :)

how do you tell if th refrac is at 20c?

Yea, I know :)

I leave mine to adjust near a radiator for about 30mins before using...

ricky
10-01-09, 21:30
so really then i do need to mix the salt to 1.028 at 25c which the true reading will be 1.026 am i correct.?

mike022380
10-01-09, 21:32
posted by sophos9 Basically, what this means is the that the ATC (Automatic temperature control) will adjust your sample to that of 20 deg C regardless and the SG changes with its temperature. SG fluctuates with temperature so 35ppt salinity at 25 deg C is 1.0264, 35ppt salinity at 20 deg C is about 1.025ish


i've been following this aswell, my refrac is atc so i require a reading of 1.025 to achieve the desired 35ppt?? providing it is correctly calibrated, is this correct?

sophos9
10-01-09, 21:37
so really then i do need to mix the salt to 1.028 at 25c which the true reading will be 1.026 am i correct.?

Forget about the SG - its the SG at 20 deg C

Forget about the 25 deg C, your refractometer will reduce this to 20 deg C (as long as its between 10 and 30 deg C to start with)

You are correct - mix 35.5ppt/psu and forget about what the SG says!

sophos9
10-01-09, 21:40
i've been following this aswell, my refrac is atc so i require a reading of 1.025 to achieve the desired 35ppt?? providing it is correctly calibrated, is this correct?

Does your refractometer have d=20/20 or 20/20 inscribed when you view through the eyepiece?

Do you have a scale which reads salinity? If so, use that...

ricky
10-01-09, 21:42
i did and the mag was 1260...i had to to mix it to 38 to get 1350..this is what i dont understand..

mike022380
10-01-09, 21:45
Does your refractometer have d=20/20 or 20/20 inscribed when you view through the eyepiece?

Do you have a scale which reads salinity? If so, use that...

it says d=20/20! :p yes it shows salinity, i will use that
you have the patience of a saint with this thread! its too late at night head hurts :laugh:

sophos9
10-01-09, 21:51
i did and the mag was 1260...i had to to mix it to 38 to get 1350..this is what i dont understand..

Hmmm... what about the other parameters?

it says d=20/20! :p yes it shows salinity, i will use that
you have the patience of a saint with this thread! its too late at night head hurts :laugh:

Cheers mate ;)

ricky
10-01-09, 21:51
see this is the thing..no-one nows whether their refrac is at 20c...i will put mine by the rad then recalibrate it i think..

ricky
10-01-09, 21:52
calc-430
dkh-9.6

sophos9
10-01-09, 21:55
see this is the thing..no-one nows whether their refrac is at 20c...i will put mine by the rad then recalibrate it i think..

Indeed, very important to calibrate at 20 deg C!!

ricky
10-01-09, 21:57
but we dont know if its at 20c..

sophos9
10-01-09, 21:59
but we dont know if its at 20c..

That we dont! Dont get too stressed, measure the temp near a radiator, adjust to 20 deg C then leave the refractometer close to it for about 30mins - thats as good as you can get!

ricky
10-01-09, 22:03
adjust what? theirs nothing to look at?

ricky
10-01-09, 22:04
i know what you mean now der..lol

sophos9
10-01-09, 22:13
i know what you mean now der..lol

Getting late now aint it :laugh:

ricky
10-01-09, 22:14
yeah..thanks for your help..i understand now..(i think)..:o

sophos9
10-01-09, 22:15
Dont worry mate, I was 2 years into marine keeping before I realised that SG aint your friend :)

ricky
10-01-09, 22:17
your not wrong..

Ducati916
10-01-09, 22:19
so in basic terms lol

if the refrac is set at 20 deg or as close to as possible, and then we mix our salt at 35.5 we will be at correct..

its the atc's job that got us confused i think, its now clear to me that its job is to set the temp of the sample to 20 deg giving a bench mark..

sophos9
10-01-09, 22:31
so in basic terms lol

:)

if the refrac is set at 20 deg or as close to as possible, and then we mix our salt at 35.5 we will be at correct..

Correct...

its the atc's job that got us confused i think, its now clear to me that its job is to set the temp of the sample to 20 deg giving a bench mark..

Nope, its not the ATC. Its the fact that SG has a positive correlation with temperature (i.e. when one value rises, the other does too). Basically, this sux and salinity does not do this! It does not matter what temperature sample goes in the refractometer as long as its between 10 and 30 deg C (refractometer will ATC to 20 deg C)

Also remember to give the ATC about 30 seconds to adjust ;)

mike022380
10-01-09, 22:39
haha think there are a few sore heads following this :laugh:
i'm mixing my water to 35ppt, this doesn't change with temperature, think thats right :o :whistling:

sophos9
10-01-09, 22:42
haha think there are a few sore heads following this :laugh:

Yea, takes some time... so many are hung up with SG however its not your friend really!

i'm mixing my water to 35ppt, this doesn't change with temperature, think thats right :o :whistling:

Yes, with a correctly calibrated refractometer a target of 35ppt is NSW, there is no evidence it should be kept anywhere else :)

Ducati916
10-01-09, 22:45
right im off to boil me head lol

sophos9
10-01-09, 23:35
right im off to boil me head lol

Sounds like a plan! I'm in the middle of reef watching, changed the flow about and the anemone has decided to make a move :o

Ducati916
11-01-09, 09:29
i had a Malu for over 10yrs, got to the size of a dinner plate. every now and then it would up sticks and go walk about and plonk its self on anything it fancied, would cause havoc....

sophos9
11-01-09, 11:14
Great isn't it :(

ricky
11-01-09, 17:20
harry whats happening with the tank mate..any offers?

maintenanceman
22-04-09, 21:35
Hi i have used h20cean from day 1 of its release and have never had any problems with phosphate or nitrate, we use around 4 to 6 buckets a week all my customers comment, on how good there tanks look even after 1 water change.