Clean up crew member for glass below the sand?

[Starganderfish]

Looking for suggestions for a Clean Up Crew member who will do a decent job of cleaning the glass BELOW the sand?
20 Gal mixed reef which is starting to come out of the ugly phase.
Ulva in a refugium (my chaeto died and I couldn't source any locally to replace it so I'm giving this Macro a go).
Current Crew:
3 x large Stromb snails
4 x Trochus snails
a dozen small Turbo's
a dozen Nassarius snails
Bullet/Brown=Barred/Chocolate Goby (dang thing has like 50 different names) who does an amazing job of sifting the sand.
I'm still having to scrape down the glass every few days but that's starting to settle down, I'm probably going to add a Lawnmower Blenny to help clean off the rocks
Daily auto water changes, daily dosing etc makes the parameters fairly stable.

But nothing I have is taking care of the algae growing on the glass beneath the sand? It's not detritus in the sand. I just took a stick and stirred up my sand bed for the first time in about 2 months and NO detritus or muck came out (the Bullet Goby really is insanely good at sand sifting). This is growing on the glass.
My Nitrates are consistently at Zero (Hanna Tester) and my Phosphates have been steadily dropping - to the point where I'm thinking I may need to start dosing Nitrates.
I can get most of it with a Nano Flipper magnet but it's a pain to dig into the sand for it.
I'm almost tempted to just stick a line of Electrical tape along the bottom of the glass to cover up that bit.

 

[Dcal]

Id get conch and other sand sifters. Having a lot of sand turnover would mean there really isn't any detritus being trapped down there fueling the algae growth. I may be looking at this wrong but that's what i have been doing and moderate success

 

[Starganderfish]

Cheers. my sand is already well sifted. The
Algae just seems to grow on the glass below the sand.
The Strombus snails are basically conches I think?

Theee of those do great on the sand surface.
The Nassarius and Bullet Goby sift the sand so there is little or no detritus.
I stirred my sand today all over the tank, for the first time in 2 months and got no cloudiness or detritus in the water column at all. Was frankly a bit surprised. The goby sifts so much that my sand bed looks like sand dunes in the desert!
It’s just that strip of glass along the front and sides at the sand level.
I remember reading that there was a particular type of burrowing snail that was good at eating algae of the glass but can’t find the page or reference to it now

 

[Sean Clark]

Scrape it.

 

[ying yang]

Put a trim over the glass to hide it ( out of sight ,out of mind) but will stop light hitting it from outside the tank also.
Will still get light from light above ovbiously

 

[Starganderfish]

Oh, I found the link I was referring to!!
Cerith Snails
“Most notably, they are prized for their ability to eliminate algal and bacterial growths on the glass just beneath the substrate surface”

Aquarium Cleaning Machines: Cerith Snails in the Reef Tank

An aquarium substrate surface can be a dirty place. Detritus, feces, uneaten fish food, film algae and other unwanted materials might pile up there.

www.algaebarn.com

And…of course you can’t buy them in Australia!! Half the fish and coral in the hobby come from Aus but we can’t buy them here!

 

[Starganderfish]

Scrape it.

Nah. Prefer to automate as much as possible. The less I have to do myself the better. It’s not detrimental to the tank, just unsightly so I’ll just cover it over I think.

Put a trim over the glass to hide it ( out of sight ,out of mind) but will stop light hitting it from outside the tank also.
Will still get light from light above ovbiously

I’m thinking this is the best solution. I know the sand is clean so the algae isn’t an issue. Block it off and I won’t see it and lack of light may well eventually kill it.
Will still keep an eye out for any Cerith snails n Aus but unlikely.
Thanks all