Plant issues - older growth getting algae quickly
I've been having, well, a lot of issues for the past while but I know how I caused most of them. But now I'm not sure what the issue is.
History, my plants are recovering from a number of things I messed up over the past few months:
1. added co2, co2 fluctuated as cylinder started running out and had to get refilled and I was having reactor issues, creating bba breakout.
2. then co2 reactor malfunctioned and clogged filter and stopped injecting co2, created ammonia spike with filter clog, and created hair algae bloom and plant die off (I didn't put co2 back in as didn't have a reactor that would work right)
3. Then light fixture malfunctioned, ordered new light but was at least a couple of weeks with very low light - some plants completely died off others had 30-50% die off
4. got new light in, plants perked up, then started dying off again - was a week or two before I realized that I hadn't upped my fertilizing enough for the higher light. And my hornwort was out of control sucking everything up. Bumped up ferts a lot and chucked 80% of the hornwort.
So that's where I've been for the past say 4-5 weeks. So my issue is, the plants have lots of noticeable new growth now especially on my hygro, however within say a week or two after sprouting, the older growth leaves start dying off. (gsa and other algae you can see on leaves in pics but think this is a symptom of die off not the cause).
I'm fertilizing micros and macros (from PMDD mixes), macros daily and micros 1x/week, and incidentally started adding extra Ca to the tank because my water is very soft (for the benefit of the snails mainly). Nitrate tests show that I have a moderate amount of nitrates in the tank so think my macro dosing is sufficient at this point. I have been doing water changes every 2 weeks about 10 gallons (75g tank), I've cut back a bit from what I used to because I didn't want to destabilize whatever good things are happening now. My lighting is an led light I got on Amazon, so I can't really say exactly how bright it is, but just judging by my plants reaction, its maybe 25-40% brighter than the dual T8's I used to have. So probably in the moderate range. I'm getting some pinks on my plants that should be pink, where they were all green or washed out before.
I'm attaching a pic of the tank on March 31, and pic of the tank today, you can see that new growth is happening, but many older "new" leaves start dying quickly. I also had an issue with green algae growth on the rock and side of the tank glass which you can see in the March 31 pic so I removed that rock and cleaned the glass and that didn't come back thankfully.
I still have some hair algae persisting here and there also although I keep taking it out, probably a couple times a week I'm in there removing hair algae and algae-ridden dying leaves. Also some of the sand has a brownish green algae growing in it, I've tried to get rid of some of it but it's hard because it doesn't really stick together. Maybe I need to do a massive pruning to clear out the old growth/algae and chuck a bunch of sand and essentially leave the roots in the ground and start over? Or maybe just keep letting the tank settle in and keep doing what I'm doing, pruning off the dying leaves regularly? Do I need more micros maybe? I have hesitated to do anything too drastic because lack of stability is what led to this. And plants aren't available here - I have these due to a very helpful person on this forum who shipped them to me, so whatever dies, is pretty much gone for good.
I would like to stay co2-free for now, because whatever happens I do NOT need any inconsistency in the delivery messing everything up again. If it comes down to it and I have no choice, I will have to look at purchasing some better equipment before going down that road again. But if I can get this going the right direction now, I'm fine with the slower growth.