Your tank is really pretty...I love the look...what kind of substrate?
I don't use chemical in my tank...sometimes they can do more harm that good IMO/E....
Prevention and finding the cause of problems IMO is the best way to deal with them than covering them up with a temp fix
With hair algae I find manual removal with an old tooth brush works the best, I will twirl it around the hair algae and remove it with a water change
Snails, I like snails and I view them as part of my mini ecosystem and they have a job of sorts, they can get out of hand when you over feed the tank, and when this happens I will trap them with a small glass jar with an algae wafer and remove them, other wise, I want some snails in my planted tank to eat the decaying plant leaves and uneaten food, they also eat some algae off the plant leaves and the trumpet snail help to keep my soil aerated to prevent aerobic spots...which is a good thing in the natural planted soil based heavy planted tanks....
Your stocking is another issue, you may want to trade your
Common Pleco (18in+) in for a BN pleco(5-6in) since the common can get really big and stop eating algae once mature. Your knife fish will also out grow a 55g, not sure what RTBS are...
Do you know your wpg? I use the shop lights with daylight bulb 6500k 40w=4bulbs (cost $20.00) over my 4ft tanks and I get great plant growth with 12h photo period as long as I change the bulbs every 6 months. I don't use CO2 or ferts in my natural tanks....
The grass looking plant..do you have a name..it almost looks like mondo grass and not a good plant for the aquarium..but it is hard for me to tell for sure.....
Your tank looks beautiful......I really love that red color from the substrate.....and once the plants fill in it will really look great.....any plans for other plants......