yes i should have stated in my post that if your keeping sensitive fish like discus you'd want to keep the nitrates lower than 20 ppm constantly, but with hardy fish like piranhas you really don't need to have them below 40 anywhere from 41-99 ppm (100 ppm and up i get worried) is fine and if12 Volt Man;4445885; said:not all the info you read in books is correct as far as real world applications go.
again, just ask around to MFKer's with big fish and/or messy fish. nitrates around 40-60 ppm do no affect growth rate and most fish thrive easily and will still be very healthy. and still grow fast. hell, I have kept big fish my whole life and I doubt my nitrates have ever been much below 40 in my big fish tanks. thats just they way it is with big and/or messy fish.
now, if you are keeping sensitive species like discus its a whole other story. but then they aren't monster fish
but for fish like hardy piranhas, this level should be perfectly fine provided the aquarist maintains proper water changes and does not over feed.
Once i again i completely aggree.
You can get them lower that's great but it's simply not nessicary.
Driftwood can't soak in nitrates nor can it produce nitrates if it rots. Wood is cellulose (a carbohydrate) theres simply no nitrogen based compounds in it to produce ammonia with (and thereby nitrate).
I have read a book on stingrays that said they can tolerate levels of nitrates up to 200 PPM ! And we call them sensitive fish this is either an example of why nitrates are not a major concern in aquariums or how books are not always correct (im 95% sure this is the later reason)