If your doing 10% bi weekly that is beyond more than enough.
%20 a month is a good number to shoot for. According to your OP, your hitting 80% a month.
Doubling that to %160 as suggested isnt changing anything. The problem is still there. Eliminate it.
You have a reasonably light bio-load for a tank that size. The fish is the biggest polluter, and you have two small ones.
in short...that's not the issue. See about reducing your feeding. I know you said you don't feed much, but consider that flakes are pretty much the junk food of the aquarium. It has its negative effects.
Raw foods are the better alternative. 1/4 cube a day would be over kill. Fish have tiny stomachs, and they are cold blooded. It means they have slow metabolisms and cant digest food like a mamal. They only need 5 min of feeding activity a day. They will do just fine if you feed them flakes once a day...and just a pinch.
AS for CuC, for such a small amount of Livestock your CuC is fine.
The goal of the CuC is to remove poop, and then do a little work on algae.
The whole 1 invert per 1g is one of the dumbest things Ive ever come across in this hobby.
You don't see my tank littered with 180 inverts(thats my volume). I have about 20-25 mixed total.
They keep my sand clean, and I wipe the glass every few days with a magnet. Filtration takes care of the rest.
If you absolutely feel you need more CuC...then just add a few at a time. But not much more than half dozen mixed tops.
But its not going to fix your problem. What are they gonna do? eat that mountain of green? Lets be realistic, its not happening. They are tiny animals, even if you got rid of the vast majority of that algae, the CuC isnt going to out pace a problem that exists.
To put my money where my mouth is...My dads nano is a great example. 2 clowns, a hammer torch, and a lawnmore blenny. All taken care of by 4 hermits, and a couple snails.
Except for an upset last week where we discovered that indeed you can have too much macro algae, (and Ive since fixed it), his tank has been doing great. Bottom line, your CuC is not meant to feast on algae that is out of control.
If you want a member of your CuC to be an algae eating machine there are two methods:
Lawnmore blenny or Sea Hare. And hands down the Sea hare will out perform the blenny.
They will eat till they starve, and shouldn't cost more than $25.
Moving on....
Tap water.Thats a good culprit. If your serious about the fix, then the best bet is RO-DI.
A descent one shouldn't be much past $125
Also lights, that's definitely accelerating the problem.
You heard right. 6-8 hours is all you should have them on for.
These two are 90% of your problem.
Now that wont show immediate results if you change this...your talking a good month or so to clear things up.
However, there are accelerators:
I am a big fan of Chemiclean red slime remover. Ive treated in the past ONCE and it never returned. There are also algae removers as well, they actually work pretty descent.
FOLLOW THE INSTRUCTIONS PERFECTLY! For $14, you will destroy every last trace of red slime algae.
Also your filtration as stated might not be enough. First thing I saw was how little LR you have.
Look on CL for some LR. Get another 15lbs or so.
And dont sell those top fin filters short. My dad uses one in his nano(30).
Hes faithful about changing his filter, are you?
I think he does over kill. He uses two pads a month. And the difference beetween his tank now and before he added the filter is amazing.
They aren't too shabby for what you pay. So don't feel like you need to scrap it, just compliment it.
Here is a few ideas:
To supplement his HOB filter, he also uses a bag of carbon, and bag of purigen, as well as filter floss that he changes monthly.
I would recommend filling a few filter socks with carbon and maybe even one with Purigen. And putting them in the back chamber. IT wont pull nutrients out as good as a reactor or canister...but you will still be having water pass in its midst's, and it will pull excess out. If a canister is an option, yo might want to consider it. They really do a pretty good job.
As for skimmer, its going to pull out alot of junk...but finding a good one for a nano sux, because most of them do just that. We gave up on ours.
Final thoughts:
Reducing the light, using proper RO-DI, and proper feeding habits( I wonder what you call a pinch of flakes), along water changes and a slightly beefing up of your filtration, will show sign over the course of the next few months.
If you want to cut that down to a couple weeks, then use some chemical treatments to kill the current algae. Just remember that the problem will simply return, that's why you have to eliminate it...not just the symptoms. OK time for bed. My .02 went a little farther than I wanted.
