On going Phosphate issues.. Need some help!

[ashr]

Hey all

My Tank: Red Sea Max 250 (66g)

So I have been battling high phos for sometime now. I just used my Hannah Checker and I am up around 0.29. I cannot for the life of me get this down to around .02 - .05 to where I want it. I use RowaPhos and chemi-pure elite.
I do a water change every 2-3 weeks of at least 5-8g. I suppose the best thing is to do some big water changes and add more Rowa but wanted to ask some of you in here. My tank is 85% SPS and the rest is LPS.

Can anyone give me some pointers on this.. I've been reefing for around 5 years and this is just getting to me. My corals look good, the colors are great but I am starting to get brown algae on some of my coral tips where flow isnt getting too.

Any help would be great..

Thanks

My levels:
Calc 300 (My doser stopped working, i usually keep it around 450 so I am getting this back up)
Alk 10-11
Phos .29
SG 1.029