Our display tank is 180 litre tank, with about 155 litres of water in it. I've been changing more than 50 litres of water a week, sometimes as much as 100 litres.
But no matter how much I change the water the nitrate is rocketing. I had it down to less than 20 parts on thursday just gone, now its rocketed to 60 again. I'm beating my head against a brick wall with this nitrate problem, and its really starting to make me think something is seriously wrong in the tank.
It has around 30 kilos of live rock in it, and a pile of corals.
2 hermits 6 snails (had more but green leg hermit likes them)
Tank has been set up for 5 months.
feeding - 2 blocks of frozen a day
I've even added some fluval clearmax that is supposed to reduce the nitrate also I removed the polywool from the canister filter, and am only putting it into my dirty great filter inside the tank, as its easy to access.
The only thing I can think it could be is the polywool that is sometimes left for up to a week. but for the nitrate to triple in a week...summert is seriously wrong
This is biting my arse soo much I'm tempted to strip the tank down and start again.
(just while writing this I tested my RO supply) my RO reading is zero (sigh)
I'm thinking of removing the canister filter all together since the dirty great black box inside the tank, although unsightly, works extremly well at clearing the water of crud. i'm wondering if something is festering inside the canister.
TBH any nitrate over 40 ppm is bad news for fish and corals ...
You know the old story , they look like they're ok , but they are suffering , but can't tell you 'cos they can't talk.
You need to bring them down mate , especially from 100 !!
Phil , there must be something somewhere is causing this. How often are you changing the wool in your filter ? I have the same size tank as you and all i run in my external is carbon and Antiphos and one sponge that is washed once a week , in tap water and dried ( to kill the bacteria ) ...
If you have 30 kg of LR in there, that should be acting as your primary filtration , i only have 20 in mine and my nitrates are never over 5 ....
Why not try doing a big water change , and then running the external and the internal with no wool in it at all , but some carbon in the external to polish the water ...
I never have a problem with water quality , or debris, the CUC should handle any left over food on the substrate , you really shouldn't need to use filter wool at all to be honest with that amount of LR ...
How much turnover do you have and is the skimmer working properly ? keeping the waste in the water column will enable it to be skimmed out ...
How deep is your sand bed mate ?
Keep your friends close , but your anemones closer ....
The only thing I can think it is, is the feeding. when I get back from work on friday, I'm going to do as advised here.
Also I'm going to put the powerheads and filters onto one switch, so that when feeding, I can turn them all off to make sure the fish are eating it all, rather than it being blasted around the tank. its a bit hit and miss on how much the fish are eating here.
The polywool is yucky after 5 days, when I think about it. after feeding 2 blocks a day, theres a good chance, that half of that food is in filter rotting away with no critters able to get at it to eat it.
suppose its not as bad as it feels at the moment, just slight changes may help clear the problem up.
spending up to 20 quid a week on salted RO is a bit much thought LOL.
Just a little worried because our bubble tip anemone was acting strange a while ago and got bleached. I fed the little bugger everyday till he got his colour back.
yesterday, he decided to split. this can be a good thing or a bad thing, good if its doing well, bad if the water quaility is bad.
I have heard that a tank can handle nitrate rockets over a short period of time, being exposed for long periods can be debtrimental (so I also heard). What unionjack said I've heard a few times from reefkeepers, and also from very well established LFS.
I still want to get low and keep low the nitrate just to be on the safe side.
Wow I wonder if that's what's going on in my tank. I can't get the nitrates down below 15 but this week they've risen to 20 even after a 28l water change. I've just cleaned out the filters and pipes at the weekend and they had a lot of old frozen food in them. I'm gonna clean them out again when I do the next water change and start to turn them off when I feed the tank to prevent this from happening again. thanks guys really good advice and probably sorted a problem that's been puzzling me for ages.
i had the same problem a while ago... the way i fixed it was 2 get 2 1200lph powerheads and put them on a spraybar (1 each end) and run the spraybar behind all my rockwork blastin water against the rock. the levels went from about 60 2 0 overnight. never had a problem since.