Brown algae takeover after years

[Flounder's Reef]

Hello I have an 250 gallon fowler aquarium it's been up and running for about 6 years well this tank is a year old but the rock and fish were transferred from my last system of 5 years.. this started as a small dime patch a quickly spread. I did add an aqua uv 57 and started to lower my phosphates which was always .40 or higher currently it's. .12. Nitrate is at 22.1. I'm not sure what it is I never really had algae issues in this tank other than cyano.. I also have a lot of floating debris.. other than the uv and running GFO I have reduced my lights to 10 percent.

 

[Lavey29]

Have you checked your RODI for silicates which lead to diatoms?

 

[Flounder's Reef]

I just changed all my di cartridges which is the problem series with two mix beds because I was reading 1 tds even with a whole mix bed that did even start to change colors

 

[JTP424]

Was the sand fresh and rinsed?

 

[Flounder's Reef]

When i did the transfer over a year ago yes it was dry sand that I rinsed

 

[JTP424]

When i did the transfer over a year ago yes it was dry sand that I rinsed

Hmmmm clean up crew?

 

[Flounder's Reef]

One urchin one snail tank has big puffers and triggers so that's not possible. I have never had a problem in six years just wondering what it is and how to get rid of it

 

[Gribbles]

I don't like how it is growing on the glass in what looks like small strands. Have you considered it could be dinos still? Numerous different species we can get in our tank and they require different eradication methods. Some don't respond to UV lights.

 

[Flounder's Reef]

That's what I thought the slime kind of strands might be dinos but I wasn't sure

 

[Lavey29]

That's what I thought the slime kind of strands might be dinos but I wasn't sure

So just turn off your lights. Fish don't need lights but algae does.