Algae... Jeeze! What am I doing wrong?

I have Green Algae growing all over everything, but the stuff that is really bothering me is the Green algae that keeps growing all over the glass.

I think it is called "Film Algae".

Environment Specs:

-Tank: 150 Gallon

-Water:
Started with 100% tap water (750ppm on TDS meter), but have been using RO water (20ppm on same TDS meter) for evaporation replacement each day (~1.5 gallons), and have been changing out ~17 gallons each week with the same RO water for about 5 weeks or so now.

-Filtration:
Large Sump-Tank with Bio-Balls.
Protein Skimmer

-Flow:
2-large blowers.

-Lighting:
480W-72" Hood (12-34" Blue/White High Intensity T-5 Bulbs)

-Time in Operation:
~2.5 Months

Is this due to over feeding, or something else I might be doing/not doing?

Please help, as no sooner do I get it all scrapped off with a razor blade, the next few days it is right back.

Thank you.

Frog...

 

You should probably just try to keep your lights on for a little less time each day. Is your tank near a window? Also with newly established tanks large amounts of algae is very common.

 

New tank?

 

Tap water is a no no. It's going to take some time to get that to cycle out. I would kill your lights for a few days, and keep doing water changes. It's not from over feeding. It's from the tap water. Post your parameters

 

I have 7 different corals, so I do not want to mess with the light just yet. Not near any ambient light.

Kinda. It is a little more than 2.5 months old.

I have 7 corals, and do not want to mess with the light just yet. Hoping that the water can fix this. Not the lighting.;D

Salinity-31ppt (1.023sg)
pH-8.2
Ammonia-0.0ppm
Nitrite-0.0ppm
Nitrate-0.0ppm
Phosphate-0.0ppm - 0.25ppm
Calcium-400ppm or less
kH (Hardness)-215ppm or less

That is all I can test for so far. Am I missing anything?

Frog...

 

I had the same issue and all I needed to do was add some chaeto into the sump and run some purigen through my canister filter. Scaling the lights back a bit in the mean time should help a bit without affecting your corals though.

 

If the tank is 2.5 months old and tap water was used at one time growth of excessive green film algae and or GHA algae is exactly what I would expect to see. Sorry I see no mystery.

Algae needs only two things to grow nutrients and light and both have been provided. As others posted it will take some time for the nutrients to cycle out of the tank.

If it were my tank I would get rid of the bio-balls, add some chemipure elite, chaeto in the sump and give it a couple weeks to see an improvement.

 

IMHO - that's your main culprit right there.
You should try to use RO/DI water which has 0 TDS. Those "TDS" will often be in the form of phosphates which are algae fuel.

 

Especially with 150 gallons of tap water at the start, you'll have a bit of algae for awhile. It'll grow until it uses up most of those resource from the tap water. A large water change with RO/DI water would get rid of a good portion of those TDS, but ultimately the algae will need to use them up. As was mentioned, another option to help speed this process up is to put chaeto in the sump to compete for some of those resources, which should slow the other algae growth or at least use up those resources a little faster.

 

Just wanted to give a progress report...

This past weekend I changed out quite a bit more water for RO water. This time hardly any algae grew back at all. There is now only a slight green sheen that grew back. Should be easy to clean, and eliminate with more water changes every week.

I have now noticed some wormy looking things, and some shrimpy looking things in the tank though. I read that this is a good thing. Is that true?

Thank you all for putting my mind at ease with your dead on diagnosis/educated opinions on the algae issue.

Frog...