Hi, tonight I found that my pH had spiked to 8.8 (from 8.1-ish yesterday)
Nothing had been changed in the tank.
I measured the kH and it was very low, between 40 and 50 ppm (about 2.8 dKH), I had previously tested it as low (80ppm) a few days ago, but I had suspected a faulty test as the system is only a little over 2 weeks old and the water was made with a well regarded marine salt (Tropic Marin Pro-Reef)
The scrubber seems to be really steaming on at the moment, I cleaned it on Sunday morning and it's almost recovered the screen now (hair algae, not as long as it was yet) in just 60 hours.
Ammonia & nitrite are zero and nitrate is below 5.
I know that heavily planted tanks can cause kH to fall and pH to spike so I assume that this is probably down to the growing algae taking carbonate from the water?
I've got the pH down to 8.2 by adding quite a lot of Sodium bicarbonate (all I have at the moment) but haven't retested the kH yet.
Questions are -
1. Does the above give a reasonable explanation?
2. What should I be dosing in terms of kH (and anything else) to counteract the effects of the scrubber and how often?