New 75g tank, 12 days since it was stocked with damsels (who have been since moved to a temporary aquarium), and I'm having real problems with pH. Its low, 7.4 to 7.8, ammonia is still off the chart. Nitrite (at .5) and nitrate (at 20) are present, but not really high for this part of the cycle.
While fish were in the tank, I used ammo-loc a few times, and Amquel+, so the ammonia present could be non-toxic. I know now that those things can screw up ammonia testing.
But the pH is really off. I've used 3 doses now of Kent's Super Buffer, and pH has actually gone down from 7.8 from the first dose.
Could this be an oxygen issue? I had a big airstone in the tank (the quad one, about 4" long), and was running it full-blast (solid 4" ribbon of bubbles).
How much aeration is needed in a tank this big?
Temp is maintained around 78F.
is right where it should be.
While the damsels were in there I did many small water changes (treated with tap water conditioner, temp and SG
set to match the tank), probably approaching a total of 40% change over several days' time.
Again, I've moved the fish into a smaller temporary tank because I didn't want them suffering (and they were starting to stress as ammonia went up).
There a little bit of fish waste that I need to clean up, but I've been dilligent about not over-feeding.
I've got live sand (about an inch, yeah, I need 3" for DSB
), and 4 small live rocks in there.
Any ideas why pH would still be so low and even dropping further? I was hoping to move the fish back in after the Nitrite peak of the cycle, but now I'm worried about the overall status of the water.
Also - one of my pieces of live rock (a branch about 8" long) has slowly been covered over with a milky-white film, smooth, sort of like a layer of rubber over it, which rubs right off with my sponge cleaner. Is that anything to be concerned about?