Ph reading all over the pkace

[geemonty]

I have recently setup a large 27gal dwc. When taking ph readings they are all over the place. It's as if different zones have formed with diff ph. It varies from 5 to 7. I keep mixing it but it just does it again after about 5 hours.

I am using tap well water ppm is about 200 ph 7, nutrients are GH maxigro to get me to 400 ppm, then I add some potassium silicate 2 ml. I ph down from there to get to about 5.8

 

[Deadstill]

Sounds like your pH pen might be wonky- what kind are you using? I usually end up replacing mine every 2 or 3 years even if stored and cared for properly, they just don't last forever.. I have a Bluelab pH pen that started doing that same thing you described when I ended up replacing it.

Maybe start off with some calibration fluid and make sure it's working properly from that? If that's not the issue then - what are your reservoir temps like?

 

[Aqua Man]

Change the battery or the probe is shot

 

[Aqua Man]

Remove the water in a glass and check it there… ive seen cheap probes do that in movement also

 

[geemonty]

Change the battery or the probe is shot

So I don't have a ph pen I use the drops, should have mentioned that. I have a ec/tds pen no ph pen for now sadly. I have never run into this. So the ph directly above the air stones is where I am getting lowest readings

 

[Aqua Man]

So I don't have a ph pen I use the drops, should have mentioned that. I have a ec/tds pen no ph pen for now sadly. I have never run into this. So the ph directly above the air stones is where I am getting lowest readings

Scoop a cup out and test that. Sounds like your solution is not mixed well yet… wait a couole hrs and try again

 

[geemonty]

Scoop a cup out and test that

I'll try that when i get home. The nutes I use sometimes don't completely dissolve for a few days. Maybe they are dissolving and changing the ph. Plants look fine for now.

 

[Moe.Red]

How do the roots look?

Any smells in the well water?

If your readings are right you are driving off co2 or sulphur or something like that with the air stones. Or your roots are rotting / anaerobic bacteria.

Have you used potassium silicate before?

 

[geemonty]

Yeah I have always used it. You know what I smelt something in the grow area wasn't sure what it was can't actually figure out where it's coming from. Plants are still young pulled them from the hydroton this morning and the roots were fine

Edit: this was a diy res. Using one of those rdx tubs black with yellow lid. I noticed light gets through the yellow. Wonder if the light getting through is causing this. Was planning on covering with something or a coat of black paint

 

[Aqua Man]

I'll try that when i get home. The nutes I use sometimes don't completely dissolve for a few days. Maybe they are dissolving and changing the ph. Plants look fine for now.

That can explain it… suspended particles of nutrients reacting with the solution when captured in various amounts. Thats about the only way i can make sense of it

 

[Buzzzz]

That can explain it… suspended particles of nutrients reacting with the solution when captured in various amounts. Thats about the only way i can make sense of it

If it keeps up I would leach it for a day or two and keep dumping it till it's stable then go lower on nutes and try again..

 

[geemonty]

ph seemed to stabalize about 6-6.5 after a few days. Using drops so cant tell with any greater accuracy than that. Plants look happy so not gonna F with it more than I have to.