Skimmer pulls ton of scum but water tested fine

[spongebob281]

Visibly my water looks fine, everything seems balanced 0 nitrate, po4, ammonia yet my skimmer put out ton of dark skimmate. Does this mean my water is dirty? All parameters are in acceptable ranges but something is not right. My sps are not opening up and some has begun to STN which is usually a sign of po4 presence. The two po4 Salifert kit i used register zero

[azcummins]

IF your skimmer is pulling out skimmate, that's good...its doing its job, especially if your parameters are ok.

Your SPS issue could be due to lots of things..wrong lighting, bad flow, bad bulbs, etc, etc. I'd ask your SPS ? in the SPS forum.

[Obi-dad]

The ions you are measing (po4, nitrate, ammonia) are not visible. The stuff in the skimmate is a combination of organic molecules, dissolved solids, etc. So you can still measure zero on the tests, and still pull out the other stuff.

[spongebob281]

youre right even if things dont show up on the tests my water could still have dissolved solids ,,i guess i just have to do more WC

[Obi-dad]

My skimmer skims a lot of gunk, but my sps do fine. How long has the tank been set up? Were the sps wild or maricultured?

The reason I ask is that newer tanks can have problems with sps. Also, if your sps is from wild colonies, or the maricultured, they have a poorer track record than frags from specimens in someones tank where the mother colony was doing well.

[spongebob281]

tank only been up running about 8 months. All frags are aquacultured. I think i need to re-position my PH so that they'll blow up all the carp in the sand into the sump where my skimmer is located.