Today I replaced 10% of the water with new RO water mixed with Tropic Marine Salt. The new water’s parameters were:

Alkalinity: 9.5dKH
Calcium: 372mg/l
Temperature: 26C
pH: 8.2
SG: 1.025

I used the return pump inside with a pipe to have some flow. I used the wooden air stone to aerate the water. I also added a heater to maintain the temperature whilst it was in the black bin. I had it running for 24 hours before using it.

I also cleaned out the brown algae by siphoning from the bottom. I left the algae (diatoms?) on the rocks. The powerheads and skimmer were also cleaned.

Finally I got hold of three T5 54W’s - two Aquablue and one 11k white tube. Installed them too.