total disolved solids - what are they?

[jacksonpt]

I've got some lingering nussiance algae in my display. It seems to be worse after a water change, though I can't really say that it is for sure. I use RO/DI water, have a decent skimmer, run a fuge, etc etc, but I can't get past the last little bit of nussiance algae.

Last week I ordered some replacement filters for my RO/DI unit, so I ordered a TDS meter as well. What exactly are TDS (I know total disolved solids, but what are those)? Initial readings show ~45 in the source water, 1 in the filtered water.

 

[kcooley]

anything but hydrogen and oxygen. Usually 1ppm is not a bad reading, change of filters usually around 2-3.

 

[Kent E]

Actually not all TDS is bad in my opinion, it could be dissolved calcium, etc. My first reeftank thrived off of a town well which had tons of calcium in it. Great for the reeftank but bad for everyone's pipes. The thing is, you don't know whats in that TDS reading unless you go to water department. They will give you a readout... but the readout is SOOO detailed that it's actually not helpful unless you are a scientist. And you'll end up just running an RO anyway.

 

[Dave VG]

Could be silica, phosphate, nitrates, copper etc

 

[MarkKlier]

Agree with Kent completely. Many of the things in tap are not harmfull, in fact we add them with our salt (ca, mg, many others) Some of the things in there are harmfull over long periods of time...depending on what you are keeping in your tank.