[boolz]

Yes, I can definitely see the oxygen bubbles coming off the plant leaves within an hour or two after the water change. My nitrates were 10mg/l. I'll get a phosphate test kit. How do you suggest I modify KH?

No, the fish deaths have not happened after using the cyano remover. Last time I used it was 4 months ago. The fish deaths have happened when the drop checker turned yellow indicating a co2 overdose.

The reason i put only two drops is because the tap water rests overnight and also the scoop of GH UP I understand primes as well. The whole purpose of adding GH UP is to buffer the RO. I doubt that 1gl RO buffered with GH UP out of 3gl water change would cause such a spike in co2.

For now I turned the co2 off and added an oxygen pump. I will measure KH tomorrow and share the results.

 

[boolz]

That's a great point. So 3KH is about 30mg/l?
Would the low KH/PH swing affect photosynthesis?

This is the link explaining GH UP:
http://www.theshrimptank.com/water-conditioners/borneowild-gh-up-90g/

Do you think a 3gl tap water 1gl RO/GH UP ratio instead could make a difference?

I almost seem to think that the new GLA co2 bubble counter I added is letting co2 randomly into the tank. Once I caught it overdosing co2 and tightened the co2 release down. That was last week when all the badis perished...

 

[boolz]

No the bubble counter is separate from the regulator. What I am trying is to limit the co2 further, from 8-9 hrs a day to only 5-6 hrs a day. This morning my PH was 7 and my KH 20mg/l