I just recently put my seedlings into RDWC . I ph water from res till I got it to 5.8-6.0. I also checked my other 4 containers to make sure ph was ok they The 2 closest to res was same n 2 farther away was slightly off maybe 6.2-6.3. I thought maybe it just need time to mix some more they are 28 gal containers. A day later they all are out of wack each with different ph ranging from 6.9 all the way up to 8.9. How can I fix this
5 different ph levels
- Thread starter GG504
- Start date
sandman83
Well-Known Member
if you PH'd before adding nutes that was your problem. Add cal-mag and let it sit for a few minutes before adding the rest of your mix. Then let it sit again for a few more minutes and take the PH, adjust a little and let sit. If you checked the PH right after adding nutes then you didn't give the buffers in the solution time to work.
sandman83
Well-Known Member
that is a different issue, probably water circulation. Check for blocks or kinked hoses? With a control bucket all the individual reservoirs "should" be very close.
I am using pvc pipe attached to containers. The only spot I have hose connected is from outlet of pump to res
Attachments
Last edited:
Roger A. Shrubber
Well-Known Member
open them up as much as possible and look at how the water is circulating. i'll bet you the ones that have the ph way off, they aren't getting circulated nearly as vigorously as the ones that are on...you have too much line for your pump, or too many sharp angles...
Well i just checked ph again they are all close except res n one near the the res. 3 are 8 and 2 are 6.6. I will ph water again to drop from 8 to 5.8 or close.
Also do u think I should get a bigger pump current pump 1110 gph n pipe is wide open 3 in with 1 in return line
Roger A. Shrubber
Well-Known Member
i don't think it's your pump, i think you've made some kind of error laying out your feed or return lines, but i'm really not a rdwc expert. they all ought to be within a few points of each other in ph and ec if they're recirculating they way they should, if you have a couple that are way off from the others, theres a reason, and it seems like it has to be in your feed or recirc lines
70's natureboy
Well-Known Member
I could never get a ph meter to give me the same reading twice so it sounds normal to me.
Renfro
Well-Known Member
Buy a better meter.
Cheap meters will however give random results lol. That may be the issue here.
Probably flow related though. It's easy with slow moving water and large sites to have areas in the totes that are not moving around and mixing.
Just a thought, to diagnose flow issues one might do a little test when the system is running and you put in fresh water. Add the nutes one at a time in the controller and watch how they flow and mix. Wait for them to mix before adding the next one. This would let you see how the flow is working. I know that GH Micro for example would be great for that as it's dark. This could also be done with a tiny amount of food coloring at the risk of staining the roots lol.
sandman83
Well-Known Member
yes the temperature will cause fluctuations in the ph.
I had this issue at first too, then I read the instructions and started calibrating my pens once a week and storing them properly. My 2 hanna meters are within .02 of each other on every sample.
Thank u guys for the response. Figured problem out it was my shitty ph meter blue lab ph pen just came in today calibrated it n check all containers they were same or or maybe .1 of n that with air stones n pump running probly could of gotten closer then that. Took pump apart it was clean but I did find clay pebbles in my return line that was causing my pump to run 40%.still a few problem but I’m getting there
Last edited: