Does RO/DI really remove everything?

[hawkfish21]

This is the second straight year this has happened to me. Both of my tanks do so well from December thru August. Then September hits and the cyano starts. Water changes do not seem to help. I even changed the filters in my Kent RO/DI. Stocking levels stay the same. I am at the point where I quit trying and just ride it out until the end of December. Has this happened to anyone else? Anyone have any ideas? Thanks.

[old salty]

It's kind of an interesting question. It really depends on what you are using to measure the water. The RO/DI I have at home would not be good enough to use in a dialysis machine (where I work.) The stuff made at work is obviously measured with a piece of equipment more accurate than a $25 TDS meter.

For reef aquariums, zero TDS on a handheld meter is fine. You may want to calibrate your meter just to be on the safe side.

[hawkfish21]

^