GHA/Red algae bloom

We have made some changes to the set up of our 40 gallon reef tank. In the past few months we have upgraded the lights from a 2 bulb power compact (directly on glass) to a hanging T5 5 bulb system. We also switched from 2 canisters to a refu/sump with some seaweed in it. We also have a protein skimmer.

Since the upgrades we have been experiencing a green hair algae and red algae blooms. It isn't red slime, the red algae is only growing on the glass.

We have added some new corals- green star polyps and zoanthids. We have 2 clown fish and 1 royal gamma. We have several nassarius snails with a few hermit crabs. My ph level is reading low at 8.0 and all my other test read 0. Our salinity has been low at 2.0 but I a working on raising that with each water change.

Our lights are on for about 8 hours. I also do a 10-20 percent water change a week.


I am not sure what to do to get the algae problem under control.

 

Hello and welcome to 3REEF!
What are you using for mechanical filtration, a filter sock, poly filter, or?
IME when I stopped using my filter sock I had algae problems. I got it under control when I readjusted my skimmer to a wetter skim (emptying it every 3-5 days) and adding poly filter between the baffles in the sump (cleaning or replacing it weekly).
Hope this helps.

 

You can try and manually removing the long strands and siphoning too. But keeping excess nutrients out of the aquarium water is one key element in eliminating your hair algae. There are many things that can add excess nutrients into your tank like some commercial foods which may contain undesirable things like nitrates, phosphates etc and overfeeding the tank is also another factor. Using a phosphate remover, RO/DI water, a good tank clean up crew ie. hermit crabs and snails and a high quality salt with no NO3, phosphates etc like Tropic Marin or similar good quality salt should really help bring the algae.