How to get pH to come down?

Soaked a few days ago with water @ pH 5.0. Runoff was 6.3, so that should mean the root zone was pH 7.6.

Soaked today with water @ pH 3.8. Runoff was 6.0, so that should mean the root zone was pH 8.2?

How could the root zone pH be going up if I am adding more and more acidic water? How can I bring it down to 5.5-6.5 (growing in coco coir).

Dude I've never seen that happen I always did my ph for coco at 5.8 and it stayed there unless I got off on the feedings and over fed or something.

try rinsing it really good before using it next time.

what is your water source? my tap water's ph rises a little over time after sitting a while.

do u have a good ph meter? cheap ones are usually inaccurate.

Your soil may be becoming a higher PH due to the build up of salts around your root zone. Lots of people encourage a "flush" with clearex which is mostly a sugar/carb mixture. I have found another product from House and Garden called drip clean which is derived from Phosphoric Acid and Potassium oxide. This product is used with every feeding in small amounts and helps to clear the root zones from salt particles and dirt to come back to a clean slate and get the most out of your regular feeding program.

http://www.house-garden.us/products/additives/drip-clean/

Thanks for the replies. The pH meter is a handheld one, very recently calibrated with buffers at pH 4 and pH 7. It's accurate. Can I just continue to flush it with water at pH 4 for a while and hope it comes down?

If you watered your plants with 3.8 ph water then you can expect to see some issues rise.

5.2 is like the absolute lowest I would ever water with. You can damage your roots with ph so low.

Don't worry about the ph coming down... Just continue to water and feed around 5.6 - 5.8.. as the coco fills up with salts it will come down.

mountainloveNW said:

Your soil may be becoming a higher PH due to the build up of salts around your root zone.

Click to expand...

Nute (NPK) salts are acidic,, they will bring it down, not up.

Could this rise in runoff ph have anything to do with Calcium binding to the coco or potassium buildup?