Most people like myself turn them every 2 weeks. If you research around here you will find from once a week to never. its a educated choice of what you want to do.How often should i change my water reservoiur and ionic feeds.
Cheers.
OK...so if I start on 9-11 at ec 1.8, and on 9-15 the ec is 1.4 do I newed to worry about nute def? I notice the color of the plants begins to lighten up when the ppms get a little low.It also depends on your res capacity, and specifically how much of it is used for each irrigation. For example, if your res is too small you may have to change it every 5 days.
The old general thumb rule is to change your res when you've added back the amount of the res. IOW if your res is 10 gallons, change it when your top-off water totals 10 gallons.
That method will compensate for any size res.
HTH
Oh i have to try the naked thing!!! i can too i am in a locked room all by myself!! might even get a tan from the lightsOnce a week.....every Monday, while the kids are at school......I take all my plants (currently 17) and put them into my bath tubs. I clean the tub well beforehand. Then I completely drain all 5 res's (three 25 galn and two 15) and break everything down and wash it with H2O2 solution (35 down to 3%). I then refill with RO water, turn on powerhead and airstones, and begin adding nutes slowly.....20 to 30 minutes between each additive......I am anal true......but this way I feel lIke I have a very strong idea of what my girls are getting. I also top off during the week with pH 6.8 RO water, and it does not change my res pH at all....all told, on my 25's I use about 6 to 8 gallons a week in add back water, depending on temps. SO..I could go longer, but Monday is gardening day...I blare Rush, or something equally fun, strip naked, and work for 5 hours...I love it. And my plants do too.......
ppm