I have a heavily planted tank with 3.5 wpg and pressurized CO2 around
25 to 30 ppm depending on pH (ranges from 6.85 to 7:00) with a kH of
8-10. 7 days ago I noticed a spike in my Nitrate to 24 ppm (the
previous weeks had been 8, 8, 4 and 15). When the spike in nitrate
happened, I stopped using the pmdd with KNO3 added and stopped feeding
the few fish in the tank. Four days after the nitrate spike I had a
big algae bloom (globs of hair algae and whitish stag horn algae).
The tank really looks bad. Today I have Nitrate of 0 Phosphate of 0,
pH of 7 kH of 9, gH of 6. Note this is a real 0 measure with the high
end Hach kit that will read .1 ppm (the dual range color wheel kit
that can read .1 to 1 ppm or 1 to 10 ppm).

So:

1. Did the bloom occur because of the high nitrate and laying off of
the nitrate will cause it to abate?

or

2. Did the bloom occur because of the nitrate bottoming out which
caused my plants to stop growing?

I think it is probably number one and I plan on letting the nitrate
sit at zero for a while whilst I just dose with my Nitrate free pmdd.

Hair grass and baby tears grow like mad in this tank.

Other ideas?


Take the stick in the eye out to reply.