Battling GHA for 6 months and losing

[Hank The Tank]

I'd been dealing with GHA for 6 months+ and losing, so I'm asking for advice.

Tank:
15G waterbox nano, no skimmer or refrigium, had chateo but died from flux treatment. Chemistry is within acceptable ranges.
Stock; cleaner shrimp, 2 clowns, 1 bi-color blenny, 1 Trouchus snail.

What I tried:
Purchased 3 Turbo snails, died.
Flux, only thing it did was killed my frog spawn. It worked on Byopsis before so I thought I give it a try
NoPox, low dosage (.5 ML daily) for about 8 weeks and it made my GSP receed and killed my Clove polyp.

What I'm considering:
Lawnmower Algae Blenny, Sea Hair Slug, Pin cushion Urchin

Need some advice which way to go:
Option 1: I'm leaning toward the Lawnmower Blenny because I have better success with fish than inverts. But i'm concerned about bio-load and the bi-color benny territory issue.
Option 2: I think an urchin may be a second choice but I'm concerned that it will die on me like the snails and release a lot of toxin and kill all the inhabitants.
Option 3: Is a sea hair slug too big for this 15G tank?

Your advice would be greatly appreciated.

 

[dvgyfresh]

I would lean towards an urchin or turbo snails I think would be well suited. Turbo snails put in work but I don’t think eat bryopsis lol and urchin will eat any type of algae. A sea hare would demolish the algae but quickly out grow the tank and must be regimes, they have the potential to die and release toxin

 

[elorablue]

I guess you’ve tried the ‘elbow grease methods’ as well?

 

[workhz]

I’d be curious about the fluconazole. What was it exactly? I’ve put it in my tank and it took care of bryopsis and gha. Also have a frogspawn and it didn’t get harmed (nor anything else).

 

[Hank The Tank]

I guess you’ve tried the ‘elbow grease methods’ as well?

Yes. I actually developed this brush+syphon device to scrub the rocks during water changes. I superglued pieces from a stiff brush head to the ends of a hose and tied a long 24" chopstick to it. It works great at scrubbing and suction at the same time. I was thinking of patenting it. LOL. But manual cleaning each week is getting real old.