ph-value wobbles like mad..

I have a little DWC Box with lemon-basil and oregano. Its only a test grow before i do weed in it.

I have a huge problem with the ph-value... here are some measurements:

11.09.12, 16:30 : ph 8,5 - before nutrients
11.09.12, 17:00 : ph 5,3 - nutrients + ph-down
11.09.12, 20:00 : ph 7,4
11.09.12, 21:00 : ph 3,6 - ph-down, to much..
11.09.12, 23:00 : ph 3,6
12.09.12, 10:00 : ph 4,0
12.09.12, 12:00 : ph 5,0 - renew water + ph-down
12.09.12, 15:00 : ph 6,1
12.09.12, 18:30 : ph 6,7
12.09.12, 23:30 : ph 6,7
12.09.12, 23:30 : ph 3,6 - ph-down, >1ml.. to much..
13.09.12, 09:00 : ph 3,6
13.09.12, 10:00 : ph 5,0 - renew water + nutrients + po-down

Can anyone help how i can stabilize it?
Also, it seems that the way from ph 6 to ph 3 is shorter than the way from ph 7 to ph 6.. i added some drops of AE Ph-down at ph 7 and it goes to ph 6, than i add some more drops and it goes straight up to ph 3.x..



tanks, p

Duplicate message.

In my experience, when the PH swings wildly like that your PH meter is either bad or needs to be calibrated. If you cant get it to calibrate, it is bad.

What kind of system are you using and what stage of growth are you in? What PPM are you running?

Hi,
sorry for the late answer, i was at vacation.

Its a Lemon-basil grow, i want to test it, before growing weed with it.

I'm using a self build system (this).

i think the problem is that its only 1 Liter of water.. the ph meter seems fine i calibrated it and tested it a few times with water.

thanks, p

projectppp said:

Hi,
sorry for the late answer, i was at vacation.

Its a Lemon-basil grow, i want to test it, before growing weed with it.

I'm using a self build system (this).

i think the problem is that its only 1 Liter of water.. the ph meter seems fine i calibrated it and tested it a few times with water.

thanks, p

Click to expand...

That might do it, try attaching a reservoir to it and circulate your solution between the reservoir and the system. Use a 7 gallon tote for the reservoir but make sure the tote is the same height as the system. Having a lot more water in the system will stabilize everything.

GreenThumbSucker said:

That might do it, try attaching a reservoir to it and circulate your solution between the reservoir and the system. Use a 7 gallon tote for the reservoir but make sure the tote is the same height as the system. Having a lot more water in the system will stabilize everything.

Click to expand...

i second that. bigger res. you can also water down your pH up/down, so you can adjust it more slowly.

if you're using tap water, be sure to bubble it for several days, not just overnight. as dissolved gases are released, the pH will change some.

only 1L water. There's your problem. Also, take it easy on the pH down. Get yourself an eyedropper.

thanks for your advice guys, ill add a reservoir and circulate the water in the box. im also planning to build an NFT system so this is a really good solution

edit: a question about that:

right now i have my bubbler direct in the box, when i have a reservoir i only need to add my bubbler into the reservoir right?
This is how i plan it:

projectppp said:

thanks for your advice guys, ill add a reservoir and circulate the water in the box. im also planning to build an NFT system so this is a really good solution

edit: a question about that:

right now i have my bubbler direct in the box, when i have a reservoir i only need to add my bubbler into the reservoir right?

This is how i plan it:
View attachment 2348850

Click to expand...

You should have an air stone in the reservoir AND one in your grow box. The more bubbles you can give them, the better.

projectppp said:

thanks for your advice guys, ill add a reservoir and circulate the water in the box. im also planning to build an NFT system so this is a really good solution

edit: a question about that:

right now i have my bubbler direct in the box, when i have a reservoir i only need to add my bubbler into the reservoir right?
This is how i plan it:
View attachment 2348850

Click to expand...

if you have the vertical clearance, what about just having one pump supply the nft, which drains to your flood tray, which drains to the res via bell siphon? some people, evidently, don't like to run ebb/flow constantly. i've never had problems running ebb/flow 24x7 with hydroton. maybe rockwool and coco get too soggy.

also, if you don't mind a little noise, have the flood tray drain from well above the water surface in the res so you get free additional aeration as it splashes down.

if you're going ebb/flow, you don't need an airstone in the flood tray. it'll be basking in air half the time.

ur PH problem could be pathagons in the water if the temp is high also

up until now i never had to check the ph of my water. it was almost always perfect. not too hard nor too soft. But since moving from there to this god forsaken, barren land im either going to have to A) buy filtered water by the case or B) get a ph reader. This water sucks, almost non drinkable...

Odd. Using common sense and very basic scientific training I have no pH swings. Adjustments, yes. Maybe try adding by counting drops. Add 5 in 5 gallon reservoirs - no more. Wait 5 minutes for complete dispersion into solution. Then check pH with a good quality meter that is properly maintained and calibrated. Note the increase/decrease in your pH. If you notice a change at all then figure it out - 1 drop/gallon shows change then 1/2 CC or 1/2 ML is going to change it far more. I knew zilch about hydroponics when I started and know little more now that I'm 2 weeks in. But I go slow and KISS!