Anyone have a clue what may cause this?

[ReefPress]

This started when I changed my salt. I was getting Red Sea Coral Pro water from my LFS then I started mixing Reef Crystals on my own with my RO/DI unit. Checked my parameters and nothing was high. I've siphoned the sand when I've done water changes, and still seems to come back. But I have noticed that it's only in the areas that the lights hits. So could it be from the light? Any help appreciated!

 

[ndrwater]

How old is the tank? Seems pretty normal to me.

 

[Claudio Olivieri]

If it's light-dependent I would venture it's either diatoms or algae, a cheap microscope would help in identifying the culprit. Personally, I like a tank with natural "stuff" growing, and the photosynthesizing growth will always be at the bottom of the food chain, to support other organisms up the ladder.

 

[ReefPress]

Tank it about 6 months. I was thinking the salt change may have. But everyone seems to say it's natural. Only other thing someone told me it might be phosphates, so I added Phosguard in for about 4 days and I don't think some of my euphylias liked that.

 

[ndrwater]

Just so we are clear, Phosphate isn't something you are going to see in your tank. Phosphate is however algae food to some extent. Looks like diatoms to me, which is a type of algae.
For quite a while, reefers were trying to keep zero Nitrate and Phosphate which has been shown to be detrimental unless you are running a system like Zeovit.
Algae blooms of one sort or another are very common in new to relatively new tanks. Ride it out, do regular water changes using RODI, and you'll be fine. personally I would stay away from Phosphate reducing products unless you Phos levels are excessively high. The only way to know is to test. I recommend the Hanna checker for Phos.

 

[ReefPress]

Just so we are clear, Phosphate isn't something you are going to see in your tank. Phosphate is however algae food to some extent. Looks like diatoms to me, which is a type of algae.
For quite a while, reefers were trying to keep zero Nitrate and Phosphate which has been shown to be detrimental unless you are running a system like Zeovit.
Algae blooms of one sort or another are very common in new to relatively new tanks. Ride it out, do regular water changes using RODI, and you'll be fine. personally I would stay away from Phosphate reducing products unless you Phos levels are excessively high. The only way to know is to test. I recommend the Hanna checker for Phos.

Yeah, I was kind of reluctant to put that Phosguard in there, and I do water changes on the regular, about once to twice per week. But thanks a lot for the info.