High phosphates

I've read this thread http://www.3reef.com/forums/algae/phosphate-high-algae-build-up-78244.html and some of what he talks about I've also...notably the little bubbles stuck in some brown/greenish stringy stuff coming off the sand and to a lesser extent, some of the rocks. I've a 110g with a 30g sump/refugium that's been running for 4 years. I've never had a phospate problem nor run phosban or anything similar. I've been trying to fathom a guess as to why the phospates spiked. I had it tested and it came out to .25 to .5. At first I thought it was from adding too much chromaplex and phytomax...but then I had the thought right before that crap started popping up on the sand that I'd used a razor blade and scraped a bunch of algae/coralline algae off the sides of the tank. I scooped some of it up, but not all. Could this have been the reason for the spike? I've siphoned up the top layer of sand twice and man does it stink!!! I've never had a stinky tank before! Anyhoo, I just added Phosban to my reactor last night so we'll see if that helps.

Any thoughts would be appreciated.

 

sounds like a diatom bloom.. i had one but it went away after 4 days, psycho mexican turbos, and a couple water changes... i would definitely do water changes and see what happens.. you using ro/di?

 

aye, using ro/di. Have only done two 5 gallon water changes. I did notice last night the 'growth' was much less than it had been so i think the Phosban's working. thank you for reply!