Nitrate Levels

[zoekin8yg]

We seemed to still be having high nitrates after water changes, so we have tested the tap water and the level in the tap water is 20ppm, so this is meaning that even a 50% water change isnt really doing much to lower the nitrates. Would using RO water help? Or any other suggestions?

Thanks

 

[andywg]

20ppm is fine. 40ppm is fine for keeping rays. Unless your nitrates is above 80ppm I wouldn't worry at all. The only scientific paper I have seen on nitrates suggests 100ppm as the upper limit.

 

[zoekin8yg]

I know 20ppm is fine but its not exactly good at reducing the levels if they have got up to 100ppm, I have dwarf gouramis and catfish, they are a little delicate for high nitrates

 

[zoekin8yg]

ps would maybe adding live plants help?

 

[Liam]

Where I live the nitrate level out of the tap is between 40 and 50ppm it doesn’t harm the fish. Yeah plants are good at keeping water clean as long as they are growing and healthy, but really with those nitrate levels you don’t have to worry about your fish.

 

[zoekin8yg]

any other ideas?

 

[eschaton]

From what I understand, live plants use nitrogen, but prefer to use it directly from ammonia, though they can use Nitrite or Nitrate in a pinch. So if you introduce a bunch, they'll mainly take up the waste before the bacteria do, short circuiting (but also eliminating the need for) the bacterial cycle. Over the long term this will decrease nitrates in the water, as you change the water, but don't expect anything dramatic to happen.

Edit: One thing you could certainly do is introduce a mangrove into a tank. They work just fine in fresh water and over a period of a few months will reduce nitrates to zero. Tanks with established mangroves often don't even need water changes done...ever! And despite having a reputation as brackish, they grow just fine in fresh water tanks. They cost only $5 bucks or so to buy each online. Only negative is you'd need go hoodless and get secondary lights for the mangrove, but it might be your best bet.

 

[blue acara]

20ppm is fine. 40ppm is fine for keeping rays. Unless your nitrates is above 80ppm I wouldn't worry at all. The only scientific paper I have seen on nitrates suggests 100ppm as the upper limit.

has there been any papers on the growth rate of fish and chances of them getting infection- between high and low nitrate on FW fish? (not saying it does affect these things, just asking)

just realised it says the only paper you have seen suggests 100ppm is upper limit-so you may not have seen any or there may not be any on the thing that i ask about...

 

[andywg]

The affects mentioned are a slowing of growth rate, rather than pure mortality.

Another paper mentioned in another thread indicates that some younger fish have their growth affected from as little as 6-13ppm, while a number of adult fish can happily survive more than 1,000 ppm.