Nitrate outta control

[lambpie89]

Hi all, been a while since my last post, prob because nothing has gone wrong with the tank for ages.

I even dared to say i knew what i was doing! ah but alas, i was wrong.

Anyways i need you help, i have 126ltr tank with 25 little fishes in it our biggest being a 6 month old pleco and the smallest about 6 trusty tetras.

My problem, the tanks nitrate levels just go off the scales in about 3 days, Ammonia and nitrite are 0 so the filters doing its job!

when't down to the local fs and bought a big supa duppa fluval external big enough for a 200ltr tank. so its defo not filtration.

did a huge clean yest, empthyed tank took all the gravel out, washed all the poo out (in tank water) and started again, reintroduced the fish and waited.

I have just tested the water again and we are boarderline 50mg/litre already.

I am stumpd , its not over feeding and not rotting plants coz they got a trim yest. undecided as to weather its over stocking but i dont think so because we have not added anything new in months and its been fine, even on a little internal filter.

Any ideas?

 

[sylvia]

Actualy it may be overstocked and you didn't have problems because the fish were smaller or have you tested your tap for nitrAtes? How often do you do a partial water change? Add more fast-growing plants to keep nitrAtes down and decrease the amount of fish you have.

 

[jimbooo]

what type of tank is it? Juwel do a nitrate removal sponge for their internal filters but if yours isn't Juwel then totally useless.

just a point though the fluval will not help with nitrate, in theory it will make it worse by converting ammonia and nitrite into nitrate faster.

water changes are the key and live plants. Maybe upgrading the tubes will help the plants to suck up more of it, please check that first though before buying anything.

 

[WILDER]

Yes water changes are the key to fetching nitrates down, same as sylvia has said what is your tap water in nitrates.