I've read about how water changes are bad for no CO2 setups, because they re-introduce CO2 to the tank, upsetting the balance that the plants have. But whenever I try to implement this in my tank, fish health suffers. I know some of you out there are doing a great job: what are you doing to make it work?
Tank: 29 gal
Light: 65watts power compact fluorescent about 8 inches off the tank- I just got a new bulb and it seemed WAY too bright so I added a wire mesh screen. Alas for no PAR meter...
Substrate: Black Diamond (sand blasting grit)
Fertilizers: Dry ferts- dose nitrate & micros every other week, and a very scant amount of phosphate once a month or so (I suspect my phosphates of being high). Root tabs- Rootmedic complete (or something from that line... he came out with new products so often...) refreshed annually
Filter: Eheim 2213
Livestock: 4 bloodfin tetras, 1 oto. 6 ghost shrimp and 2 dozen or so red cherries, 4 nerites, some ramshorn snails, MTS, and planaria
My underwater plants were doing okay, but within a week of putting on the new light (its been about 2 weeks now) I noticed what looked like new BBA specks over all the anubias leaves, so I added the wire screen over it. It is now more dim than I would like, but I'm afraid to take it off for fear of the algae.
I have plants in riparium planters to absorb extra ferts and shade the tank a bit. My african violets are absolutely flourishing, they bloom nearly non-stop (probably 7 weeks out of 8), which is why I suspect my phosphates of being high (also, they have been high in the past).
I know with the high phosphates and planaria, that overfeeding is a possibility. I honestly try not to- they are fed no more than once per day, about 5 days per week (I forget some days), and I try to keep the amounts small.
I have been doing ~40-50% water changes once per month. I use 1/2 tap and 1/2 RO water.
Any suggestions for fine-tuning my setup? Obviously the recent algae growth is a concern, but I also feel like I have always been missing something in my tank setup - the algae has never gotten out of control, but its always been around, also. Sometimes the plants grow faster, sometimes they are just at an even pace.