Local Water Quality

[Dazm]

Hi,
I have recently moved to a new house and water supplier and thought it would be worthwhile checking the quality of water I'm going to be using for my proposed tank, inverts and fish.
The comprehensive results are....well.... comprehensive. The mean results of each parameter are as follows, I'll miss out the ones that are neglible.

residual desinfectant - 0.28 (not in a unit of measure :huh: ) is this chlorine?

Ammonium - 0.008mg/l

Conductivity - 785 microS/cm

pH - 7.27

Copper - 0.043mg/l

Fluoride - 1.27 mg/l

Chromium - 0.966 microG/l

Nitrate - 8.035 mg/l :unsure:

Sodium - 31.6 mg/l

Chloride - 38.8 mg/l

Sulphate - 101 mg/l

Total organic carbon - 1.33 mg/l


The water is "hard" and I am unsure how my RO will cope with it? Would it be better to run it through carbon and a sediment filter rather than the RO?

Are there any compounds which stand out particularly as being benificial and detrimental?

Sorry its a bit of a dry subject.


Many thanks, Daz.

[kim]

Calcium, carbonate, phosphate ? If the water is hard, I assume that they are pretty high.

Anyway, at that conductivity (implying TDS around 560 ppm, so there's a lot of stuff you didn't list) I think that you need RO to be safe. Plus the usual carbon and sediment pre-filters, and possibly also DI after the membrane, especially if phosphates are high. Your water is at the "nasty" end of the scale for the UK.

Even "good" stuff like carbonate can cause imbalances in your tank. Eg standard salt mixes assume you use pure water - but if your source water contains 10 dKH to begin with, once you are finished you may be over the top. And the bad stuff will become even more concentrated if used to replace evaporation from the tank.

Since the water is hard, a flushing mechanism for when the RO system is not in use (preferably automated, so it comes on for a minute or so a few times per day) will help prevent the membrane from being fouled with scale. You could even use a water softener in advance of the membrane, but while I've read about this in many places I don't know anyone who has actually done it.

kim

[Dazm]

Calcium, carbonate, phosphate ? If the water is hard, I assume that they are pretty high

I've just rang the relevant person and the calcium carbonate is 278, mag carbonate 210, silicates 8mg/l :o and phosphates 1mg/l :o .

I see your point about there being an imbalance even if the water has some beneficial compounds. The main problem is that I think this water may be that bad that I am going to use a large amount of water to produce the quantities I need for initial fill, top up's and changes. with a high rejection rate and with a water meter I'll be throwing most of it down the drain.

Since the water is hard, a flushing mechanism for when the RO system is not in use (preferably automated, so it comes on for a minute or so a few times per day) will help prevent the membrane from being fouled with scale.

I'll have to investigate this further, i didn't know there was an RO like this, thanks. Although I do have a softner of sorts but it is a "Siliphos" unit which doesn't remove the compounds but keeps them in suspension I believe, this would only make things worse.

thanks for the info Kim.

Daz

[fire999]

Might i sugest using a RO and DI unit to remove most of that stuff, I would not use tap water without it IMO.

[fire999]

Sorry Kim ,,,,, i did not read you reply..... ( much better than mine ) :blush:

[dod]

Daz,

I suspect that the residual disinfectant is probably the total residual oxidant (TRO?), which I believe is the test thats usually used for chlorine. No idea what units they use though.

Dod