Sorry - same old boring subject

[diggozo]

Nitrate (NO3) / Nitrate-Nitrogen (NO3N) Levels

Apologies for coming back to this subject but I have a problem in understanding it fully.

My tap water supply is showing a Nitrate (NO3) level of >25mg/l or >6 NO3N and after my fish have swum around in it feeding and pooping the level increases to what is generally considered to be 'uncomfortable' for freshwater fish and which has me in a mild state of panic . . . or am I over-reacting ?

To deal with the problem I have used bottled water (v.expensive), Kenwood filters (100 litres per filter only - goes nowhere) for my daily changes and am really scratching my head as to how I can get the Nitrate levels down . . . . RO is out of the question.

BUT - roaming the Net tonight I discovered that the USEPA reccommends a safe level for home drinking water at a Nitrate-Nitrogen Level of 10mg/l which is equivalent to a Nitrate Level of 44mg/l

So far, so good . . . . . . my new question . . . if it is OK for me to drink water at this level of Nitrates why is it bad for the fish to swim in it ? I know they absorb water through their skins but I am taking the stuff directly into my system and am still standing (just) . . . can anyone explain and please . . . keep it simple.

[lereg15]

I am just a newb, but you'd also be able to handle being in 23 dgree weather, whereas your fish can't. A humans immune system is much different than a fish, therefore needed adjustments are necessary to help the fish to adjust, since being in a controlled setting, they can't go somewhere else to get rid of whats ailing them.

I'm sure there's alot better and more info out there, but I hope you can see what I'm getting at.

[Indigo]

Someone please correct me if I'm wrong, but some water conditioners will help detoxify Nitrates. Seachem's Prime comes to mind. I'm not sure what you have access to, but perhaps simply treating your tap water with Prime (or other water conditioner that says it detoxes Nitrates) might help.

Anyway, here's the Prime website: http://www.seachem.com/products/product_pages/Prime.html

Good luck!

[Blinky]

Are you at all interested in keeping live plants? They use NO3 as a food source. If you kept some hardy plants in low light they would use up some of the nitrates in the water, if you supplied more light and possibly CO2 (DIY CO2 costs almost nothing to set up and if you're ambitious you can DIY lighting as well) they'd take up even more (the faster they grow, the more nitrogen the plants will take up as a food source).

[daveedka]

Bear in mind that nitrates are the indicator we use to monitor pollution in the tank. High levels for extended periods are harmful to fish, but more importantly allowing nitrate levels to increase in our tank is also allowing other pollutants and toxins to increase. These pollutants and toxins are as much if not more of the problem than the actual nitrates. If you have a starting point of 25 mg/l and you keep your tank below 40 mg/l it would be the same as my tank at 15mg/l. Most of us here target a level below 20, some will say 40 is ok. It's the folks who go into the range of 60+ long term that are risking their fish. Dependng on what level the tank is actually rising to you may want to adjust maintenance and or filtration to keep it lower, but you probably aren't hurting your fish. You are just starting at a different benchmark level to begin with.

As far as drinking it, you drink the chlorine also, and it would kill your fish.
Dave

[diggozo]

Thanks everyone for the helpful replies and also for not being too scornful in answering my stoopid question re "my drinking/fish swimming" . .grovel, grovel.

My tank is well planted and this, together with daily water changes must be what is preventing the nitrate level from rising much higher than the tap water level.

Am much assured by Daveedka's reply and explanation of using the nitrate level as a 'benchmark' . . something I had not heard of before and will allow me to sleep well tonight . . . . thanks again.

[happychem]

Concerning the long term toxicity of NO3 I have a sneaking suspicion that the "long term toxicity of high levels of NO3" has more to do with the pollutants associated with the NO3 that with the NO3 itself.

This is completely unsubstantiated, of course, merely based on suspicion that the original statement comes from hobbyist experience and not from any controlled experiments that expose fish to pure NO3 without associated biproducts, fish and tank derived NO3 with all the associated toxins and a control with no NO3 or toxins.

In other words, I think that you're fine. Just treat your tap measurements as your blank when doing tests on your tank, i.e. subtract it from your tank measure.