Ph of dwc

Hi guys,

Hope someone can help.
Doing my first dwc grow, and every time I lower my ph to around 5.5, I find that it's gone all the way back up to about 7.5 within a few hours.
I have to lower it a few times daily, does anyone know why this could be happening?

maybe root rot?
you should only adjust pH once a day.
more info from you is needed. water temps, EC/ppm, nutes/additives, etc.

Can you give us a few more details please. What kind of nutrients are you using? What is your e.c., usually
Did you check your air stone, is it functioning properly?

Just started out, it's just a seedling, no roots touching the actual water just yet.
Haven't checked my ec or ppm, haven't bought a metre yet.
Nutes are Advanced Ph perfect, maybe that's what's fucking with my ph?
The air stone is fine.

Never used dwc myself, but I am using the ph perfect line for coco, I find the ph perfect to be a bit of a bs line, if my ph is high @7.0 straight from the tap, the nutes drop it to only about 6.5, for coco I like to be around 5.5 so I end up adding ph down. Once I get it to around 5.5 or 6 it stays put even with the nutes

ph perfect has buffering agents in it to regulate the ph. shouldnt be 7.5 though. I am afraid youre either gonna need new nuted that are not buffered, or you are gonna have to ride it out.

dont bother trying to adjust anymore, youre just introducing too much acid for no reason. it might grow well where its at. are you using hydroton or rockwool? rinse them well?

Type of pH adjuster? pH meter bad or needs recalibration.

Use the AN that you have then buy something else.

Calibrate your meter. That is a REALLY fast swing. Especially since you don't even have roots in the water? Are you top feeding? What media are you using?

Sometimes hydroton can cause your ph to really really spike. I had a run with a batch once that I was constantly adding ph down. I eventually found a reason for it, something about the age of the hydroton, can't remember. Anyways.. something is not right.

Doesnt really make sense. It should hold for weeks.

If your pH is jumping like that you might have a pathogen issue. If your water temps are not kept chilled into the sixties, this becomes a more likely suspect.

The usual cause is simply light nutrients. The plant's removal of nutes and addition of exudates can definitely push pH upwards pretty quickly. I take this as a sign I can increase nutrient strength.

If you have a water top off system, that's another possible culprit. Adding fresh water always raises pH.

@Velvet Elvis adding acid doesn't screw with the nutrient balance half as much as adding pH up does. As long as you're adding pH down to keep the water in range, you aren't going to hurt anything by using it.

legallyflying said:

Use the AN that you have then buy something else.

Calibrate your meter. That is a REALLY fast swing. Especially since you don't even have roots in the water? Are you top feeding? What media are you using?

Sometimes hydroton can cause your ph to really really spike. I had a run with a batch once that I was constantly adding ph down. I eventually found a reason for it, something about the age of the hydroton, can't remember. Anyways.. something is not right.

Click to expand...

Interesting, I hadn't heard anything about pH changes in hydroton as it ages... does it climb?