Welp, I think the 75 may be hitting rock bottom (or at least I hope so).
I'm concerned about internal parasites, I've got a small ich outbreak, a hair algae explosion, and some cyanobacteria present. All of this has occurred in the last 1-2 weeks.
So now I'm:
1) Treating food with epsom salt for internal parasites
2) Treating the tank with external parasite (ich) medication
3) Ordered another heater to help bring temp up (I think ich may be from stress due to low temperature, tank is in the garage and its winter)
4) Will be hand removing as much hair algae/green algae as possible
5) Hardcore gravel vacuuming
6) Picking up 4 Siamese Algae Eaters to help with hair algae (whenever my LFS gets them in stock again)
7) Considering doing a blackout for 3 days.
8) Adding a phosphate removal substance to my FX4
9) Cutting down on lighting every day
Ugh, hopefully all of this work leads to a healthy, balanced tank. I really can't wait until I can look back on this thread and be happy with where the tank is at.
On the bright side though, everything in the 125 has been great now for 2 years, and was great for the previous 2 years all of the inhabitants were in a 75! *Knock on wood*