"Karen Garza" wrote in message
hlink.net...
Michi Henning wrote:

"Karen Garza" wrote in message
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There is little to no nitrate present in my three tanks. I consider all
three of them to be fully cycled. Shouldn't there be a small amount of
nitrate? Are the plants using up what little nitrate there is?


Seems unlikely. Your fish load isn't all that high (except for the
third tank), but you don't have that many plants either. In the
first instance, I would suspect the test kit. Get another one
and try with that. Alternatively, your water changing regime
may be such that you are removing sufficient nitrate to get
below the detection threshold of your test kit. (Another brand
of test kit might help with that.) A (far out) possibility is that
you have anaerobic nitrate conversion to NO2 happening in
your substrate or your filter. (Apparently, that is happening in
most tanks to some degree, but not quickly enough to stay
on top of the nitrates altogether.)

Cheers,

Michi.


Okay, I think I may have to try a new test kit then. I suppose it's
possible that I am removing the nitrate with my water changes. I do a
minimum of one weekly 30% water change and gravel vac. Sometimes I do an
extra 30% water change each week. I didn't think it was too much water
change, but I could be wrong. Wouldn't it be possible (maybe even
preferable) to even do a daily 50% water change if the fish are used to
it?
Thanks

Karen


it is likely that your weekly 30% water changes reduce your nitrate below
measurable levels. I do weekly 50% water changes in my heavily planted 77g
tank and dry dose ferts twice a week including a 1/2 tsp of KN03 (nitrate)
and I still don't measure much nitrate. Your plants will also be using up
nitrate. I wouldn't worry about it, seems everything is running o.k for you.
As far as daily 50% water changes are concerned you could do that if you had
the time but why bother. You fish in fact become accustomed to the schedule
of water changes you keep them in. To suddenly go from 30% weekly to 50%
daily could prove harmful. You could gradually increase you water changes
but 30% weekly is more than what most do.

Rick