green algae advice

[AllieBdot]

Lots of back story here but in a nutshell my several of my fish got mysteriously sick last week. We tore the tank apart to move them all to a treated hospital tank. While we were fish free we did a big water change (40ish gallons in a 110gallon tank with tons of love rock). We siphoned the sand and added new carbon and some other special filter media that is supposed to absorb toxins in the water.

Now we have green algae taking over the display tank and the water is cloudy. As fast as we clean the glass it comes back. Our huge BTAs are shrunk down and shriveling. We put a couple fish with no symptoms back in the display tank due to space and bullying issues. Our copperband and yellowtail damsel are doing a funny little twitch with their heads.

Water parameters are back to where they were stable prior to this.
8.2-8.4 pH.
9.6 alkalinity.
No amonia or nitrites.
Nitrates and phosphate both at around 5.
Temp is 78*
Only thing we are dosing is calcium because ours runs low.

We've reduced the light intensity. Any other suggestions what is causing it and how to fix it?

Also worth nothing, we have no sump. 2 hang on the back filters. A canister filter. A protein skimmer and a powerhead. Never had a problem with filtration until this week.

 

[Spare time]

Do you frequently siphon the sand (assuming you meant cleaning and not removing)? If the water is cloudy, you can try a UV sterilizer like a green machine which is pretty cheap.

 

[Spare time]

Also phosphates at 5ppm is extremely high so that would be the cause of your algae.

 

[German51]

I recently had an issue similar to yours but mine was very cloudy water and red algea. I just did water changes evry other day for a week and after that it was still a bit cloudy. It started going away a couple days after all the water changes. I think I had a bacteria bloom and im positive it had to do with the quality of my water. I have a RO Pure Plus 4 stage filtration system with a reverse osmosis storage tank and I decided to check the TDS from the filter and sink and they were basically the same. The sink had a TDS of 151 and the filter was 130. It had been a while since I changed the filters and once I did it now reads 0 TDS and havent had any problems with algea, cloudiness or anything else so far. I could be wrong and could of been something else but im pretty sure that was the problem. Good luck.

 

[AllieBdot]

Do you frequently siphon the sand (assuming you meant cleaning and not removing)? If the water is cloudy, you can try a UV sterilizer like a green machine which is pretty cheap.

We normally just siphon the sand in the front of the tank. We had all the rocks and coral moved to catch the fish so we gave it a good clean beneath the rocks.

 

[AllieBdot]

Also phosphates at 5ppm is extremely high so that would be the cause of your algae.

I meant .5ppm

Also phosphates at 5ppm is extremely high so that would be the cause of your algae.

It's only .5 typo

 

[Spare time]

I meant .5ppm

It's only .5 typo

That is still decently high. Consider using some type of phosphate remover. I would say the most common range in reef tanks is between 0.1ppm and 0.03ppm (not to say that this is a strict range that must be followed, but rather a typical goal).