Revitalizing my FOWLR into a mixed reef tank?

[david_finlayson]

I'm not sure if I have 8 years of experience in salt water aquariums or 1 year of experience 8 times!

I have had a FLOWLR set up since 2013 - my first and only saltwater tank. Over the course of my first year, I purchased a clown fish, a 6-line wrasse, a blue damsel fish and a Valentini Puffer (the star of this tank). Sadly, I lost the puffer a couple of years ago, but, the other three fish are still with me after all these years. My clean up crew is long gone. I've never restocked the tank, so it is just these three small fish. I'm ready for a change. I'd like to try raising some easy to care for corals and some new invertebrates but first I want to get rid of an infestation of nuisance green hair algae that has taken over my rock.

This tank has always had problems with GHA and I just learned to live with it. Regular water changes and black out periods of a week or more have been ineffective at removing it. My parameters appear to be good with so few fish, so not sure what to do next. Removing it by hand is impossible. I don't want to add more fish or corals until the tank is ready. What should I try next?

Here are the details of my tank:

Equipment:

- 16"x16"x32" - 37 gallons acrylic tank
- live rock (originally a mix of real rock and a home-made rock the previous owner cooked up)
- HOB reef octopus skimmer
- Power head/heater
- RO/DI water filter (always < 2 ppm TDI after filtering, just changed all the media so 0 ppm on last water change)
- Finnex StingRay LED lighting (on 8 hours per day)
- Instant Ocean Salt (just replaced with Tropic Marine)

Parameters:

- NO3 < 1 ppm
- PO4 somewhere between 0.08 and 0.12 ppm
- anything else I should test for?

Stocking:

- 1 clownfish
- 1 small damsel fish
- 1 6-line wrasse
- a small population of Asterina starfish (I remove them when I see them)

 

[KC's CNC Creations]

with no more rock then you have, if it's not all secured together i'd just remove it one at the time, give it a good scrubbing with a stiff bristled nylon brush, rinse in some tank water (saved from a water change), then spray it with 3% hydrogen peroxide, let it sit for 5 min and then rinse in tank water again before returning it to the tank.