Algea and Film Problem

[agrabow837]

I have a 90 gallon tank that has been running for 6 months. I have a cleaner shrimp, 4 medium turbo snails, 2 percula clowns, 1 yellow tang, and 1 naso tang. I recently added 5 hermit crabs and 10 small turbo snails.
I seem to have alot of green algea on the sides of the tank. There isn't much on the live sand (about 100 lbs). There is some on the live rock (about 50 lbs right now). I added the additional turbo snails in the hope that a larger clean up crew would help. Thoughts?
At the same time, there seems to be a film forming at the top of my tank. I generally do a water change of 5-10 gallons per week. What is this film? I do not have a protein skimmer. Is this the reason the film exists? I am running a Fluval405 cannister filter.
Any advice would be appreciated.

 

[renogaw]

i would most emphatically suggest a protein skimmer. you'll almost puke from the smell of the stuff that your fish are living in and you aren't removing from their water.
i would check your phosphates, light, etc. is this your first breakout of algae? seems a late bloom but normal for new tanks. get a magfloat scraper and you can use that to get it off your glass, but snails will be the best answer. i scraped my brown algae off my glass because it was getting so bad, but since then my snails have it covered.
do you have any powerheads pointed towards the surface of your water? you may not have enough agitation. i havent had this film so i don't know what it is.

 

[agrabow837]

No powerhead. The fluval return gives pretty good circulation. What type of powerhead do you suggest? Where should it be mounted? Should the return be under the water level or above when mounted?

 

[renogaw]

how much water circulation do you have? only the one pump?
you should have minimum 900gph circulation in your tank (10x-20x your water content). i have a 75 with just over 1k gph (if i do my calculation right). i have 2 maxijet 1200's pointed at the surphase, 1 maxijet 900 around the center of my tank, and a mag500 as my return from my wet/dry.

 

[agrabow837]

Looks like I need to get a power head and see how that helps things. Rio or maxjet? What do you think? I have a 90 gallon so what should the GPH (gallons per hour) be?

 

[renogaw]

i've heard multiple horror stories about rio powerheads. my lfs even suggests people not buy them and he sells them.
if you have just fish, you should have about 900gph water circulation. a maxijet 1200 puts out around 275 gph.
if you're getting into corals you are looking to have around 1800gph.