15 gallon res. ph seems to rise to fast

i am growing a recycle system. drain to recirculate. i am in veg cycle i am using rockwool cubes. i phd the cubes to 5,7 when i first got them. no every time my pump turns on. 3 times a day. the water that drains back into the res is alot higher in ph. like 6.6. its kinda a bitch to ph the water 3 TIMES A DAY. any one have any ideas?
thanks for your time

Hi -

I had the very same problem with my first hydro grow (25 litre reservoir)
what I did was airate the water using & airpump & airstone
a good day or two before I needed the water, & did my Ph
during this time, the air will help with nutrient uptake
& also helps evaoporate the chlorine in the water. Basically by
doing this it seems to stablise the ph so it doesnt
fluctuate. I would only check every
2 days after doing this & it worked great for me.

Give it a go...

thanks a lot. im using an airstone now. does the evap of the clorrine cause the ph to raise so much? should i do a flush to get the cubes down. or would that put my month old plant into shock

I think the chlorine does play a part in the ph levels, once this is evaporated it
definately seems to stabilise, also the airstone gives the water a good mix/air
Are you using a liquid or powder PH down? I found that the liquid versions are much
more stable than the powder types. 6.6 is a little high for Hydro but I did have some crazy ph levels when I first strated & the plants were fine, you will be surprised how hardy & tough they are. I would just carry on feeding as normal get your reservoir prepared with your ph around 5.5 & get your nutes in with your water as well if needed as the nutes can
cause the ph to rise & fall. Basically prepare your soulution about 24/48 hours before it's
needed so you have a nice stable, chlorine free, well airated water...

What medium are you using? purely rockwool?

im using rockwool to coco. im still in the rock wool stage of my veg.thaks for all the advice. u r the shit. i use the gh liquid ph down

Nice one, hope all gos well & the advice was useful. The liquid ph down from GH should be fine it's the powder ph down/up that seems to flutuate & give crazy readings.

Good luck with your grow!