I tested the water today using my new test tubes with rubber stoppers and Mohr pipette. It was delightful, as the rubber stoppers work far better than the plastic caps that come with the API test kits. I won’t buy these test kits again, as I again was not able to confidently determine whether my nitrates or phosphates were elevated or zero. It depends how I hold the test tube against the printed card and the lighting! I guessed they were not in fact zero, and just in case, I am doing another larger water change. I changed about eight gallons four days ago, and will do another eight or nine tonight.

I also calibrated my pH meter today and found my previous readings in the target 8.3 range were in fact wrong, and my pH is actually about 7.9. I followed a procedure from Reefkeeping online magazine where I aerated water from my tank using outdoor air and also indoor air to determine whether additional aeration would help. My tank water tested at 8.0 initially, and after one hour aerating outside, the pH rose to 8.2. The next test water started at 8.0 and was aerated inside for an hour, after which it tested at 8.0 to 8.1. Additional aeration therefore might help my tank a little bit, but I would need to run an air line from outside to be effective. I am therefore opting to use Seachem Reef Buffer that raises pH to 8.3. These products are apparently not recommended in general, but the Reefkeeping article says they are acceptable in the case where pH is low due to excessive carbon dioxide indoors. The product will raise alkalinity, which I will need to monitor, as mine is already somewhat high since I am keeping my salinity at sea level, 35ppm, which is on the higher end of the typical reef aquarium range.

So, I added 3tsp (15g) buffer to the buckets of saltwater I am mixing and heating, and I’ll retest the pH of the tank after doing the water change.

In other news, the red gorgonian has started falling apart and is probably about dead. The yellow one barely opened a few polyps today after I moved both to directly in front of a powerhead, as I have tried medium and low flows to no avail. The orange whips are doing well and fully open, as is the purple one to the extent I can keep the algae off it. I also removed hair algae from the sides of the refugium and part of the main tank last night, both so I could see better and in an attempt to export some nutrients. I placed the new macroalgae from Indo Pacific Sea Farms in a net in the refugium for now, but it is a bit crowded and I need to come up with a better solution where it won’t crush the crabs.