Algea question

[dcherry]

I have a 6 year old 30 gallon tank.

1 Protein Skimmer
1 Fluval 205 (phos guard, Chemi Pure - connected to a bio wheel
1 Current Nova Extreme Pro Saltwater T-5 6 bulb
1 under power head with rotating flow outlet
1 Maroon Clown
1 Pin Cushion Urchin
1 Rainbow Lobster
5 soft corals
8 Snails
Hermit crabs

Additives I use
Essential Elements
Coral Viet
Coral Accel

Water changes with RO water

Green algae has taken over and most of my coralline has disappeared after turning white.
Phosphate levels have increased but I can't tell why. Nothing has died and I have not added any life to the tank for over a year.
On of my polyp mats is also struggling to stay alive.
Any Ideas

 

[tangs rule]

Test your RO water - if not already done - get a tds tester from lowes/homedepot/amazon ~15 bucks and see that your RODI unit is making good water. The filters&membranes in them crap up and eventually your output water has junk in it. any readings from tds tester higher than 4-5 would require action.
bulb age - as bubls age they "red shift" producing higher & higher red & orange light. Not visible to the eye - but any flourescent bulb older than 6-8 months is suspect and any over 12 months consider trash. Most people run a 8-10hr daily cycle on their lights and 6-8 months is all the life your gonna expect.
Also - many urchins actually munch on coraline alage. Some may not eat as much as others but I used to have a blue tuxedo that ate it exclusivley....wasn't problem though, I had more growth than 1 could eat on 120# lr.
Others may want to see water numbers - so post them

 

[tangs rule]

O - and I'd not add any additives to my water for a while till this clears up - a good reef salt mix and good rodi water to start out is all your tank needs....regular 10% (20% per week+ if tank is having problems) should level out any bad parameters. If you cannot test for things like iodine/mag/strontium/other trace elements - be very careful adding "element additives" as it can be overdone.