It seems like I've found a good combination of parameters for my setup and the tank is turning around. The way I arrived here is somewhat unusual though. A couple months back I decided I wanted to add snails to the tank to get some help keeping things clean. I tried adding ramshorn and pond snails from my other tanks and they died within a few days. At night they were fine, but during the day they would try to climb out of the tank or sit in their shells at the bottom. After they died, the shells dissolved very quickly, so I figured I should try increasing my
pH by increasing my
KH. I did it over a few weeks, adding a couple snails each time until they were comfortable. A KH of 2.5-3 seemed to be the lowest amount that made the snails happy and I've stuck with this for the past 3-4 weeks. I haven't changed my dosing, remineralization, or CO2 significantly throughout this process.
Here is the tank as of today. It is growing healthy overall and the majority of the plant groups have no major algae growth on them. The biggest problem groups are Rotala mexicana 'Goias', Helanthium 'Vesuvius', and Pogostemon 'Kimberley'. I haven't replanted the Rotala since before the KH changes so I'm guessing I need to pull it up and toss the old growth. Pogostemon is growing algae on a few stems that are doing a weird stunting sort of behavior and I probably need to trim off the tops. Every other group is growing pretty normally at this point, including my Syngonanthus 'Rio Negro Giant'. It's started expanding and I'm hoping I can grow a nice group of this plant in the next couple months.
My dosing is outlined below just for reference, but I personally think that increasing KH was the major thing that helped. I inject CO2 using reactors that build up a CO2 bubble on top and this was causing my pH to be depressed under 5 for a large portion of the day. Immediately before CO2 came on, it was at most 5.3-5.4 because I had so little surface agitation degassing CO2 overnight. Keep in mind the tank crashed after 1.5 years, which is roughly when aquasoil would stop buffering effectively and provides a small amount of support for the pH/KH hypothesis. Now my pH is ~7.5-7.6 fully degassed and at max CO2 it's 6.1-6.2. This clearly works for the snails and plants, which makes it work for me. I have a lot of old growth that I need to trim off still, but I'm holding off until the snail eggs hatch. I'm hoping this crew will help me clean up the remaining algae to get the tank 100% back on track. Also, don't take this post as me saying you need to have a pH around 6.1 or above to have a successful tank. This is just what seems to be working best for me in this particular setup and I have no idea why. I've had tanks with lower pH run well in the past, so this probably isn't a universal fix for everyone having similar issues.
Since the tank is moving in the right direction, I've begun getting some brownie ghost 2011 ready to be moved. I've kept the same plant growing since ~2016 (it's very visible in some of the tank pics in my first post) and it hasn't been kept in a high tech tank since I moved in 2021. It's getting some very nice color in my 10 gallon tank (and hair algae!) and I'm excited to see if it can maintain it's color in the 120P.
