Odd as it says tap is fine for this machine. Id be expecting roots soon but still no sign.It depends. If it stays clean of any nastiness, keep using it till there's roots. I needed to change my cloner out every few days in the summer cause it would get hot and start growing bacteria, but I could easily go 2 weeks without touching it in winter.
Also depended on if I was using tap or RO water. I almost never have bacterial issues with RO, tap water WILL have pathogens in it.
I rarely saw roots before day 7, usually 10-14 days, never saw the fast rooting times claimed by others.Odd as it says tap is fine for this machine. Id be expecting roots soon but still no sign.
You need not change it except in between sets of clones.I recently got a x stream aeroponic cloner and just wondered how often I should change out the water? The instructions say nothing about it. Day three and no sign of roots yet.
The machine stays on 24/7 as per instructions.
Thanks