Thanks for the advice on the lighting -- that was a relatively easy fix using a full spectrum adjustable LED
light bar with a timer. I scrapped the Marineland/integrated lighting altogether and the atmosphere in the tank is much better controlled.
Now back to the chemistry in the tank. I was lulled into a false sense of securityóas a novice is apt to beówith the low/stable ammonia levels. Now the Nitrites have spiked up to 8ppm. I have been re-reading the Nitrogen Cycle posts and clearly this is a natural progression in the Cycle. It would appear that the beneficial bacteria has grown to a level to consume the Ammonia levels but the bacteria needed to convert the Nitrites to Nitrates are not sufficiently grown yet.
I have continued with 2x/week 40% water changes and have been dosing the tank with Fritz Complete
in hopes of avoiding Nitrite poisoning. The fish are all active and eating, but as I understand it -- nitrite poisoning occurs over time, so I am on the lookout for signs of stress in the population. In the meanwhile, I will cut down of the feeding (frozen bloodworms, algae wafers and tetra flakes). My concern is the water changes as I try to work through the Nitrite spike. I read somewhere that water changes can slow down the growth/production of Nitrite-eating bacteria. Is there any validity to this? Or is it a matter of degree and perhaps the aggressive (40%) water changes should be scaled back?
Again, the fish are doing well as far as I can tell.
As you can see from the current picture posted, I keep the aeration robust and while I don't test O2
levels, all indications are that the water column is well oxygenated.
Update on Fish population:
2 Red Velvet Oscars
7 Diamond Tetras
1 Pleco Catfish
3 Green Cory
2 Zebra Cory
1 Pink Cory
2 Mystery Snails
2 Nerite Snails
Water temp - 79F/26C
Nitrate 60 PPM