View Full Version : Live Rock An Adequate Filter ?
i have a aqua one 620t tank which is 24"x24"x18" it has about 25kg of live rock in it and about 119 litres of water in , one tang,one coral beauty, one green chromis , and two black clowns +a royal gramma also 8 differnt corals and i am getting quite high levels of nitrate building up in under a week (i do 10% water change once a week) i was talking to one of my friends that said my trickle filter could now be hindering the breakdown of nitrate is there any truth in this ?
he says that my live rock sould be effitient enough to break down the nitrate its self now (its been running since beginning of october.
i was told that i should never mess with the ceramic media in the bottom of my top trickle filter but when i remove the particle filters (one white one black) the ceramic hoops are swimming in small grey particles like dirt which my friend says is fish ****
nitrate 50 mg/l after three days (after water change)
ph 7.9
calcium 380ppm at last look
wayne in norway
06-01-06, 22:05
Trickle filters are fantastic at oxidising ammonia to nitrate, but do nothing at all to help reduce nitrate to nitrogen gas. So they are sometimes described as 'nitrate factories' - great if you want to be shot of ammonia and don't care about nitrate , but ...... you have a problem.
Live rock on the other hand is less efficient at dealing with ammonia (or rather still good, but not so ruthlessly efficient) but does also get rid of nitrate. It's complex structure allows for the accumulation of a suite of different bacteria that do both the oxidative and recuctive parts described above. There are various theorys on where the reduction takes place - I personally believe that on the microscopically very complex surface of the live rock is a layer of anaerobic bacteria in a thin film covered by a layer of aerobic oxidative bacteria. Working together they get all the way thro' the nitrogen cycle to nitrogen gas.
A fair question is why don't these bacteria get rid of the nitrate in my water? Well I think it's because they're shielded from it by the layer of aerobic bacteria, and they selectively don't let it pass (why should they?).
So my advice would be to slowly (couple of weeks) pull the bioballs out. Let the LR do it.
Hi,
Sorry no-one answered immediately :wacko: . This isn't the most active forum on this site and you may have been better off posting it in "Reefs" if you wanted an immediate reply. :thumbsup:
Anyway, live rock is a very efficient filter. However even that has its limits and you are very overstocked (perhaps by a factor of between 2 and 3 times in a tank that is less than 30 gallons if you're also looking to keep corals) - do you have a skimmer on the system at all? Live rock also has to have very good circulation around and through it to function at anywhere near peak efficiency. What sort of circulation do you have in the tank itself?
I suspect unless your corals are very hardy you're going to have a problem keeping them for an extended period in a tank with such a large bioload. You may be onto a loser because however much filtration you have running, the bioload is simply too much for it to process. Tangs require a lot more room than a 24" tank to display anywhere natural behaviour - most would advocate 100+ gallons for them.
I would be disinclined to remove any filtration media until you're sure that the remaining filtration can handle it - I suspect it may not. :(
HTH :)
John
i am running two 1200l/h power heads and also puriigen instead of a skimmer and rophos sponges these are in the trickle filter compartment
in what way am i over stocked as in rock or fish ? or corals ?
14x turnover from your powerheads is borderline adequate, more would be better. What corals have you got in there?
With corals you can't overstock - you can have every inch of your live rock covered and it would be fine as far as bioload goes. However, the problem with corals is compatibility - depending on the species they can sting and/or overgrow each other. Depending which has the more potent sting/faster growth rate/both then that species "wins". Some soft corals also engage in chemical warfare by expelling chemical agents into the water column. Some people run carbon to minimise this and adsorb other pollutants. By and large when you're setting up you can't fill the tank with corals from a costs point of view so it's only after several months or longer that this becomes an issue.
Live rock - you can't overstock per se, but the rockwork needs to have an open structure to allow good water flow through and around it to allow efficient filtration. A tight "wall effect" usually results in dead spots of little or no water movement which then tend to increase nitrate. Without a picture though it's hard to say what your position is just using the weight as a yardstick because live rock does vary considerably in weight.
It's the fish that seem to be overstocked in your tank - as a rule of thumb (and it is only a rule of thumb) in a reef system you should be around 1" of fish per 4 gallons. So in your system around 9" of fish is a good starting point. You can add more if once it's stabilised your parameters are good and you have enough experience to gauge whether the system will cope with more. Also bear in mind that it's the potential adult size of the fish and not its size now which needs to be used in the calculation otherwise you could be fine now but 6 months down the line be way overstocked again due to the natural growth of the same fish.
I'm not familiar with puriigen :blink: so don't know what it does or is supposed to do? As far as it replacing a skimmer, I've not heard of any chemical product that would do that and would doubt its viable long-term use. Are you in the UK?
RowaPhos is used for adsorbing phosphates from the water which if left to accumulate can cause algal blooms and impact the health of the corals too. Most people fluidise it i.e. run it in a filter that keeps it in suspension but know that some also use sponges - not sure of the relative merits of either method.
Do you use reverse osmosis (RO) water when topping up your tank for losses due to evaporation?
John
Hi, i just looked up purigen one of it's claims is nitrate removal :(
The main problem with fish stock is the tang. Are you over feeding, as it is very easy to pollute a small tank.
John.
wayne in norway
07-01-06, 10:05
As has been pointed out you are very heavily stocked. I would advise getting a skimmer to remove a lot of organic wastes before they decompose to ammonia and go into the nitrogen cycle.
Hi,
Have had a good read about purigen on www.reefcentral.com where it looks to be in relatively common use and has been for a while. There are a lot of threads on there where it is referred to. It may be an idea to have a look yourself rather than rely on hearsay on my part <_< . But for the record it seems that most, if not all, people that use it on there just use it as an additional chemical filter media rather than a replacement for all other types of filtration.
I don't know nor can provide information on using that process - it seems a little (read very) dubious to claim that 100ml of this can filter a 100 gallon tank for 6 months :blink: :blink: as the packaging blurb seems to suggest, but in actual usage by reefcentral members it seems to be supplemental to normal filtration methods rather than replacing it. People stil use skimmers, run carbon and phosphate removers as well as this stuff. It does appear anecdotally to produce notably clearer water when used in association with other products.
John
I tried Purigen and did nothing for my high nitrates, good flow, skimmer and RO water has lowered mine from over 50ppm to nearly 0ppm since october
i have found out the nitrate levels where low the problemm was my test kit it was 4months old but that didnt seem too old but tested a water sample at marine tech my local fish shop and it was fine fhave replaced test kit with test strips seem a lot better than the three lots of drops and powder test kit that i had:o
Get rid of the Tang ( 24" tank too small )
Get a good skimmer
Do a few large water changes ( about 25 to 40 % )
Read up a bit more on keeping corals , and the condiyions they need to survive.
Hope all goes well for the tank. Keep us updated
Could try using Salifert test kits , they by far the most acurate.... Never seen strips before !!!!!!
Glad to hear the levels are lower.. But you still need a new home for the Tang :(
Hi,
Purigen is effective IME but I would tend to use it as part of my first aid kit to rectify problems, rather than as the prime means of filtration.
Prevention is usually better than cure so cutting back to an appropriate level of stocking and doing what you can to remove pollutants before they break down into ammonia/nitrite/nitrate (i.e. by protein skimming) should have a big impact on water quality.
Stick with it and good luck!
Keith
Hi.
I have the aqua one AR620 the slightly smaller version of yours (92l) i have 15kg of live-rock. I have 1 Ocellaris Clown, 1 purple firefish and a yellow watchman goby paired with a pistol shrimp, aswell as the usual clean up crew. It is a FOWLR setup at the minute and has been running for 3 months, i plan on turning it into a reef setup in the near future, what lighting have you gone for and how is it working out so far? got any pictures of your setup? For the trickle filter i have removed the ceramic noodles and the sponges, i have kept in the filter wool and carbon bags, i have also added some live rock rubble, this setup works well. I would also advise to cutdown on the amount of fish you have by two, one of them being the tang as it will not thrive in this size tank. For this tank a skimmer is not neccesary if you keep up with your water-changes 10-15% weekly, although a skimmer would be beneficial to any system.
Hope this helps.
I read with some interest about stocking levels and live rock filtration. From the tank details given below, what would be a safe recommended level of fish inches? The Red Sea skimmer will shortly be replaced with a MCE600 and the tank is about half full of LR with much more to add as finances allow. Currently I have 2 x damsels, 2 x clowns, 1 Blue Wrasse and 1 Coral Beauty, as well as 2 starfish, clean up crew, soft corals (about 6) and a Malu nem. Many thanks.
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