Quote Originally Posted by urbanfarmer
No, the nitrates are fine. Flood and drain grow beds rarely have problems with oxygen, but you mentioned root rot... The correct way to calculate the required gallons and relevant surface areas is tedious and unless you already have an understanding of it, it's really too much to post here. Stick with the general "pounds per gallons" and "square feet grow bed per pound" rules of thumb provided by Oliver. The rest will be trial and error for most folks, which is part of the fun; so, enjoy it!

Anaerobic bacteria would cause denitrification, which causes an increase to your pH: 6NO3- + 5CH3OH => 3N2 + 5CO2 + 7H2O + 6OH

Anyway, the shell grit in a removable bag of some sort a great suggestion to adjust the pH problem. Not only will it bring it up, but it will allow the solution (water) to buffer itself.
What do you mean the Nitrates are fine? I was asking if the nitrates are a good way of measuring the health of the system. If you have lots of nitrates in theory you would lots of fish waste right?

Currently I must not be experiencing dentrification because my PH keeps lowering steadily.

Also, I have shell grit in my system. As well as organic free range egg shells. They sit in my particle filter in the gravel from my drive way.