Help - Green Algae and Metal Halides

[kgrutzmacher]

Been learning a lot here over the past 18 months but now I have a problem. I recently upgraded from 210W of PC lighting to 2 - 250W metal halides and T5 - Actinics. I 'was' leaving the MHs on about 5 hours a day and the Actinics about 8 hours. Within a few days - I got a ton of green algae growth on all my rocks. I have gone to the local fish stores and they have offered up the following...

Feeding the fish too much - I now cut back to every 3rd day.
Too much phosphate - I need to get my water tested
MHs not 'burned in' yet...

Their advice is to just wait it out - let the fish and urchins eat the algae and things will eventually clean up. Just wondering if I am missing something.

At this point - I only have the MHs on for about 4 hours a day and the actinics are not on at all. The tank is not near a window and this only started after I put in the MHs.

Any advice?? All the fish are doing fine... Just a lot of green algae

75 Gallon Tank - 5 Gallon Sump - Trickle Filter and 2028 Eheim Canister

 

[ccCapt]

Welcome to AA!
Lots of green algae = lots of excess nutrients.
You need to test for phosphate and run GFO (granular ferric oxide) in a reactor to drop the phoshpate levels in your system.
What is your nitrate level?
Do you use RO/DI water for top offs and water changes?

 

[austinsdad]

I too would be very interested in your phosphate and nitrate levels.

Also, what do you feed?