my first questions are what type of food are you feeding?
are you using RO/DI water?
what type of clean up crew do you have to control it?
what type of substrate do you have?
Usually having CC in a nano causes blooms because it harbors the nitrates from old food and fish poop between it and the water in such a small tank goes bad quick!
i would recommend getting a emerald crab and possibly a few cerith snails and margarita snails, they do good work on most types of Algae without having to go chemically, if it fails after that point then i would try something else. hermits sometimes help but they will also take out your snail population over time.
in such a small tank, the type of food you feed is critical. there are a lot of flake foods that cause Algae blooms if you feed slightly over what your fish can handle. same with the gelatin type foods like the "San Fransisco Bay" brand frozen foods which cause huge blooms in my tank and make my skimmer go nuts. when i feed PE mysis everything is fine, when i feed PE i still put the food in the net and run it under water to thaw it out and remove any excess nutrients on the outsides of the food before i feed it.
you can also try things such as microbacter 7 to help add bacteria to the tank to remove nitrates and phosphates but this will show no results until you can remove the hair Algae yourself, then it will just help at preventing it from growing back.
You could also try turbo snails. I had 2 large ones that destroyed my HA in a week. I also reduced the light cycle to 6 total hours with only 4 hours of white light ( I use LED as well). I manually removed as much as possible, bumped up my mg with Kent Tech M for a week and started bacteria dosing as Justin suggested and inside of 10 days, it was gone and has not returned.
My problem started with my use of RO water with no DI and not rinsing frozen mysis. RO was producing 10-15 TDS at the time of the outbreak. I started the DI with 4 water changes prior to the above changes and I think that made an impact as well.
I battled it on my 75 gallon in the beginning what a pain. I could tell you what finally worked if you want.
Seeing as how the tank has been up since July, you might just be seeing some of the stuff dying off in the substrate and rock. Also make sure your temperature is pretty stable. I've had that cause algae blooms.
Run some gfo in media somewhere in your back chambers. Try to feed pellets only, if your fish will eat them. Put your fish on a diet. Be very religious about water changes (make sure your using good quality water). Obviously you can't use tangs or foxface in a 28g. Starving it out is the only sure way to success.
Sorry Henry Hill, I know your pain. I'm not going to tell you what you should and should not buy. Only because I tried everything stock wise(snails, crabs, fish,) to rid my 8g of HA. I found that if the HA is to long nothing would touch it.
I fought for better then 6+months. I lost a lot of zoa's, from being choked out. Even those in the SB on their own plugs. Finally I quit buying any. I started researching what *algae* really is and how and what it needs to grow.
The algae was there from the beginning. In the LR. The LR is leaching nutrients in the way of die off. Of course light, water source, feeding all played a part but still. I couldn't do anything but find something to out-compete it. But until then what about the stuff that's already taken over my tank. How do I get *RID* of that. I didn't just wanna keep it from growing ya know.
This is what I finally did. While still picking as much as I could, on a daily bases no doubt.
I bought some, Marin-Chem Stop Hair Algae. It worked wonderfully! I applied it to the worse and largest areas. Making sure to stop any and all flow during application. Allowing it to sit for about 20-30 min before returning flow. Within 48hrs the treated spots were clean. No harm to my corals at all. Except for the zoa's I applied the stuff to directly still the loss was worth the results.
What I liked about the stuff? Is it smells like black Licorices!! YUM! Oops sorry I love black licorices.
I have no more HA in my tank at all. Haven't even had a re-occurrence. I'm not trying to sell you on anything, just sharing what worked for me with the Long Hair Algae.