Oddness with my water quality.

[AlaskanCorydoras]

Two of my tanks are currently reading 0/0/0 with ph 7. No Ammonia, no nitrite, no nitrates. The Ph isn't a surprise, since I use a buffer on my water-replacements. (My tap water is 7.6. Not good for my poor cories.)

All my tanks are planted to some degree. My most lightly planted tank has java fern, duckweed, and an EXTREMELY impressive ball of Java Moss in it. (The moss tangled around the artificial tree I bought ages ago when I first got back into the hobby. . . and now you can't even see the fake tree. And the moss is swarming with Endler's fry.)

Both my 90 gallon and my new 55 gallon are showing no nitrogenous wastes at all.

I suspect this is a result of the Massive quantity of duck weed in each of the tanks. Both tanks normal plants are growing well, as well, with a sort of red waterlily putting up red lilypads (Making me want to get frogs to go on them. . . but I doubt the frogs would stay on them, sadly.) the Vals growing like the weeds they are, a Wysteria getting eaten by all commers. . . etc. etc.

It is ammusing me that I'm thinking about possibly having to ADD nitrogenous fertilizer to the tanks. Heck, the water comming out of my taps is dirtier than these two tanks.

[L number Banana]

Not such a bad problem to have but when I had happy NEW_TANK readings like that, I was told there may have been some spikes that I missed. It was also suggested that my test kits were either expired or not accurate enough. Worth checking first.

Another idea may be whatever you're using for additives (Amquel +, prime plus etc) Some have ammonia etc removers, do they mess with the tests at all? It is possible for the plants to be using the ammonia up before it has a chance to get high enough to read. But there should be some reading of the other two at some point. What do you mean by buffering? Would there be something there that would mess with the readings? Did you use something like a used filter to cycle the new tank?

Maybe your best bet would be to take a sample from each tank and get your LFS to give you a more accurate reading. 0,0,0 sounds a little too dead, if you know what I mean. Also your city website should have their water readings so you can see what their NO readings are naturally. I frequently have triple zero readings but it always shows to be just a moment in time and something sneaks up a little here or there. Especially first thing in the morning when your plants aren't coming off a big growth day.

[AlaskanCorydoras]

My 90 gallon, at least, cycled long ago. Spikes are quite unlikely at this point. Well developed plants, and well developed biofilters. I've checked the readings with two seperate tests, of two seperate companies, and neither gives me readings on any of the nitrogenous waste. But my plants are growing well. . .

Another idea may be whatever you're using for additives

My philosophy is "If it aint broke, don't fix it." I don't USE additives, other than the occasional plant fertilizer.

Oh, and my LFS uses the same test kit as I do.

[L number Banana]

Doesn't sound so weird for an older tank to have occasional blank reading. I was more curious about the new 55gal. If it's not bothering you that the readings are always blank, why did you call it odd? I must have misunderstood the original post. I thought you were looking to find out why that was happening. Sounds like things are just ducky then.

* by additives I only meant dechlorinators etc, whatever buffers you are using etc.
I use additives - Flourish Excel - love it, love it, love it