Ph altered water reverts back over time?

[rattlingdags]

Hi everyone
I just have a quick question I wanted to ask since I've searched loads of ph related threads but not come across the answer and I'm curious.

I put in my PH down into the tapwater (tapwater is PH 8) that had stood open airing for 24hrs and checked the reading with my little aquarium strip tester - the result was clearly in the 6.5 PH colour.
I watered my baby seedlings and then as there was still water left over I continued to use this water over the following days. When I checked the water again it was back to the pre-altered PH level of 8. My poor seedlings.

I'm going to PH my water as I need it from now on but this regression in the water is not something I've read about - yet anyways.

It goes without saying that I'm a real nooby at indoor growing, only grown veges outside, but am I the only one caught out like this?

rattlingdags Reviewed by rattlingdags on 12-03-2010. Ph altered water reverts back over time? Hi everyone I just have a quick question I wanted to ask since I've searched loads of ph related threads but not come across the answer and I'm curious. I put in my PH down into the tapwater (tapwater is PH 8) that had stood open airing for 24hrs and checked the reading with my little aquarium strip tester - the result was clearly in the 6.5 PH colour. I watered my baby seedlings and then as there was still water left over I continued to use this water over the following days. When I Rating: 5

[rattlingdags]

Its not only me afterall. Found others on a fish forum According to a poster there water that has been PH adjusted does indeed revert back to its orginal PH level over a matter of several hours.
Nothing was mentioned on the instructions of my tester kit, a little note added in would have been handy.
Happy growing everyone

[WashougalWonder]

Yes, this is as the buffers cancel the acids/alkalines and there is still imbalance and I think I read somewhere it is because the water is absorbing ? CO2 ? from the atmosphere and that caused the PH to change. I like at least a 24 hours sit before checking PH, but never had it continue to change after the first 24 hours....but I use about 5 gals a day total, so I just let one bucket a day sit out.

[rattlingdags]

Thanks for the comments WashougalWonder, for me this has been the first of many learning experiences to come
I just gave my kids their drink of freshly PH'd water and touch wood they'll get over having such a rooky mother mucking them around.

[Horsemanrocks]

What youâ??re experiencing is your tap water outgassing.

Iâ??ll take a wild guess in that your water is likely well waterâ?¦.at least water that hasnâ??t been exposed to the air for long.

Outgassing isâ?¦.de-acidification. So as the water outgases (de-acidifies) the Ph can only rise.

When I do a res changeoutâ?¦.I must correct for the rise in Ph for at least 36 hours.
Airstones accelerate outgassingâ?¦and I use a lot of air, so longer than 36 hours is certainly not out of the question.

Hope that helps,
HMR

[oldmac]

Excellent point HMR :thumbsup:

I'd rep ya but you know....gada stread some love around.

OM

[GetThisOrDie]

Ive used my PHd water several days after and the PH never does that. So well water does it moreso than tap?

[rattlingdags]

Thats interesting about GetThisOrDie's well water not doing it.

Our tap water comes from underground, treated and I think mixed with other recycled treated water. By the time it gets to us its a steady PH 8.
Maybe I should try leaving the water to outgas for another couple of days and see if that makes a difference. Its worthwhile trying a few things as it would be handier to be able to mix the water for a few days in advance.

Thanks everyone for your input, much appreciated

[Horsemanrocks]

Iâ??m just explaining the process of outgassingâ?¦..your experience will be totally individual.

Letâ??s imagine that your well water is pumped out of the ground and sits for an extended period of time in a tank that is only ¼ fullâ?¦..it will outgas to some extent in the storage tank before it ever gets to you.

How long was it in the ground?

Did it rain recentlyâ?¦.so the water was fairly fresh?

What is the make-up of the local geology?

Does the water get aerated somehow in the processâ?¦..etc, etc, etc.

GetThis,

So well water does it moreso than tap?

Just because of itâ??s confinementâ?¦..meaning less opportunity to outgas.
Likely not say river or pond water because of itâ??s exposure to air.

OM,


The process happens, but youâ??ll have to deal with it on an individual basis.


HMR

[yetibear]

Ive used my PHd water several days after and the PH never does that. So well water does it moreso than tap?

:thumbsup:


I've stored ph corrected water (tap) for 4-5 days and it stayed exactly correct!