Let's talk about nitrates

[KentFishFanUK]

Ok so I've been thinking about my nitrate levels. I can't seem to keep my nitrates under around 40-50 ppm, which is the same as what my tap water reads as well so though I do some water changes they don't bring nitrates down. I have quite a few plants and I can only assume they are keeping up with the added nitrates from the cycle as my level never seems to go up but they aren't enough to get it significantly lower than what comes out of the tap either. 

Online I've seen massively differing opinions on what is a good or even safe nitrate level for fish. On average people typically say don't let it go above 40 but plenty of experienced people say they don't worry about it until it's much much higher. Aquascapers seem to suggest keeping it at around 20-30 ppm for plants. On a loach forum I've seen claims that nitrates over 10ppm will kill hillstream loaches, now I kind of saw that as a bit of exaggeration or them being purists - they also mostly suggest that hillstream loaches are only suitable for biotope set ups - than anything else but then my lovely little hillstream loach did die after around 10 days in my tank for unexplained reasons so maybe there is more to it? 

I've ordered a pothos and will see if I can use that to suck up some more of my nitrates before getting another hillstream loach but in the meantime I wondered what everyone else's thoughts/experiences with nitrates were? 

Does pH affect how toxic it is in the same way as ammonia? Or anything else that means 40 ppm of nitrates in one table/water is not the same as 40 ppm in a different tank? Can a high nitrate level be indicative of a different issue? Are some fish literally so sensitive they would die at over 10ppm? Is there another piece to the puzzle I'm missing? Is there a way to test oxygen levels? Is there another way to reduce nitrates?

[Guppysnail]

As for oxygenation add  airstone or sponge filter more helps everything. The testers are very expensive.  Nitrate removal is very hard I battle high source water nitrate. Options are ro water. Jug water or they sell hose attachment filters and sink attached filters for nitrate removal that are inexpensive but they also remove calcium magnesium and other minerals as well. I have not used them but I extensively researched nitrate removal. Mine is usually 20 legal is only 10 here but by the time it gets to us it’s 20 sometimes 25. 
I don’t like to play chemistry remineralizing I am not the scientist type so my combat is pothos and stuffing my tanks like a jungle with things like pothos hornwort fanwort brazillian pennywort and frogbit ( frogbit was the game changer it eats nitrates like mad. It’s crazy how just 2 plants (they multiply every few days) added to each tank after forever struggling a bit still totally fixed my issue) frogbit actually did better than pothos 

[KentFishFanUK]

@Guppysnail yeah exactly my decision, didn't want to go down the route of RO water etc and playing chemist if I can help it, hopefully when my pothos arrives it will do the trick! I have salvinia as I think frogbit would get wet in my tank and die off. 

I have a small sponge filter plus an air stone plus an internal power filter with its output above the water line so lots of agitation etc and I don't think I should have any issues with oxygenation but if there was an easy way to test it to make sure I would. 

Legal limit only 10? That's good, it's 50 here! And apparently our water treatment makes good use of that leeway! 

[Guppysnail]

On 7/28/2021 at 5:57 AM, KentFishFanUK said:

@Guppysnail yeah exactly my decision, didn't want to go down the route of RO water etc and playing chemist if I can help it, hopefully when my pothos arrives it will do the trick! I have salvinia as I think frogbit would get wet in my tank and die off. 

I have a small sponge filter plus an air stone plus an internal power filter with its output above the water line so lots of agitation etc and I don't think I should have any issues with oxygenation but if there was an easy way to test it to make sure I would. 

Legal limit only 10? That's good, it's 50 here! And apparently our water treatment makes good use of that leeway! 

In my pleco tank I have high surface turbulence. I bought a betta feeding ring that suctions to the wall and put my frogbit in that so it stayed in one place didn’t shade my other plants and didn’t get too wet and die. It works great. 

[KentFishFanUK]

On 7/28/2021 at 11:00 AM, Guppysnail said:

In my pleco tank I have high surface turbulence. I bought a betta feeding ring that suctions to the wall and put my frogbit in that so it stayed in one place didn’t shade my other plants and didn’t get too wet and die. It works great. 

That's pretty much what I've done with my salvinia so it didn't shade out everything else (except I bodged it with airline tubing etc). Might have to switch to frogbit if it's better than salvinia then! 

[Guppysnail]

It’s better than pothos I don’t know about salvinia. It serious 2 plants took me from 40 to 20 in 3-4 days and made a baby plant in a 20 long with 2 adult bristlenose 4 huge 2.5-3 inch mystery snails cpd’s 100+ shrimp and a ton of bladder snails. 

[MH1]

I don't understand all the angst over nitrates. Yet another example of misleading/incomplete/simply false information being spread in the age of the Internet. Decades ago, serious aquarists believed the less often you changed the water the better. To some extent that's true. People are more likely to experience problems if they try to micro-manage their aquariums than they are if they simply left them alone and let nature do her thing. That's assuming of course that they have proper bio-filtration in place.

From what I've read on the subject, controlled experiments confirm that nitrate levels below 200 ppm are perfectly safe for fish. If you don't believe in science, the Stendker folks, who breed and sell world-class discus, raise their fish in water with 200 ppm nitrate levels.

[KentFishFanUK]

@MH1 well that's kind of what I thought after listening to @Cory on the subject and looking at some articles etc but then as I couldn't figure out why my fish died I started to wonder if there's more to it, it's a pretty prevalent opinion on the internet for some reason. 

[MH1]

There are many reasons fish die. Chlorinated water change, previous bacterial infection, internal parasites, old age, poor genetics. Nitrate poisoning should be last on your list.