Algae problems please help!!!

[martym]

I have a algae problem, brown, green,red and purple. My nitrates are around 5ppm I have no phosphates. I have 2 daylight bulbs,1 50/50 and one actinic in a 55 gallon tank. From what I've read when you have no phosphate or nitates you shouldn't have the algae problem I'm having. Please help!!!!!

[Aquattro]

Martym, welcome to Canreef! Hopefully we can help you out. How are you measuring PO4? It's possible that you have it, but it's bound in the substrate. What have you got for substrate, btw? Please describe the flow in your tank, and anything else you can think of. Do you skim, what do you feed and how often, do you dose kalk, etc.

[martym]

Brad, thanks for the welcome. I have a seaclone skimmer,fluval 304,aqua clear, and a 802 power head. I am measuring with hagens po4 test kit and the test doesn't even start to change color. The substrate is crushed coral. I feed flake in morning and either frozen krill or blood worms in evening. I also have phosguard from seachem in the fluval. At $70 an pound it better be working. It is also suppose to remove silicates.

[Aquattro]

Well, I hope you're getting the phosgard at J&L, or some other poular place. I see it's about $30 per 2 liter container, not sure about weight.
The canister filter can act as a sink for nutrients if the media isn't changed often. I think Randy Holmes Farley had a recent article on phosphate removers, might be worth looking at. I'm sure you know that a major source of PO4 is the food, with frozen food containing juices being the worst. I always rinse any frozen fod I feed to help remove phosphates.

Do you have any live rock in the tank? Crushed coral can hold a fair amount of detritus, which in turn can hold (undetected) phosphates. Also, if your bulbs are really old, it's thought they can help trigger the growth of PO4.
What is your water change schedule? And what is the source of your water? If you don't have an RO unit, it might be worth it to you to buy water from the grocery store. You might not need the expensive seachem stuff. Let's see what else others can add to this, since my area of specialty isn't algae/cyano problems!