Softening water does not make the water harmful to your reef. Nor does it make it perfect for the reef. It really depends on the quality of the water that you are putting through the softner.
FWIW, I started my reef with soft water. Didn't know at the time, but my soft water contains phosphates. So I bought a 6 stage RO/DI and mounted it (hehe) under the kitchen sink. My soft water has a TDS of 350 PPM. After going through the RO it has a TDS of 13 PPM, and zero phosphates!
hi.
Do you mean you want to use water softener? It replace the calcium with sodium, so the amount of ions in the water is the same, just that sodium is "softer" than calcium. If you use softened water for topoffs, the ionic balance may be off if your water supply is hard.
But if your water is soft naturally, it is certainly better than the harder water with the same parameter (besides calcium and other "hard" minerals). One thing is that RO and DI will last much longer.
Hey louey, is there any way you can hook up your RO to the water supply before the water softener? If so you can increase the life of your membranes by not making it remove the added salts and other "contaminants". Just a thought.