The art of keeping a pH constant?

[Spaventa]

In my defence - I was talking generaly about ph but with reference to o/p original point, I said that folk should adjust ph gradualy and recheck as needed. Anyway, when it goes up and down like a yoyo, thats ph swing caused by reeasing salts in the water and the media by adding too much ph down - I mentioned ph drift because of the wording of the thread title. Other than that, I stand by 5.2 - 6.0 in veg and 5.5 - 6.2 in flower, over the course of a res correctly sized for the grow.
Mine empty a res a week in veg but as many as 3 peak flower.

 

[Haps]

What he said, all three times.
H

 

[chosen]

Ph does flux from time to time,but one thing that I'm curious about is your full nute regimen. Use a ph stabilized nute such as floranova, sensi A & B, or even Ionic. It will help you some. It's not the perfect solution but it will help some.

 

[TanzanianMagic]

Im having alo of trouble with keeping my pH constant.. I dunno if there is anything wrong or this is just the way things are. Im new to hydro, so can someone plz tell me if it is normal to adjust the pH to around 6 one day, and two days aftet it will be around 8 or maby even higher?.. Im using buckets that each holds 2 mothers, the res are around 20-25L, and I use GH pH buffer..

I would really apreciate any help, cuz the plants are showing severe signs of pH not beeing right, and that figures.

Try ph-ing your feed water twice with ph-down. Apparently, the buffers that keep your ph going back to 8.0 need time to 'sponge up' the acid. After that, you can keep the ph low by using very little acid. I've tried it and the ph is holding at a constant level. Something to do with 'permanent hardness' of the water.

You should also aerate your water, to get rid of carbon and chlorine, either by stirring it or putting in an oxygen pump.

So ph your feedwater, come back 12 or 24 hours later and ph it again, in the mean while stirring it every so often.

 

[foaf]

There is no rhyme or reason as far as I can tell.

I am doing my 4th grow using the exact same nutes, ro filter, media, system, lights.... and the ph has done different things each time.

once, there was almost no drift
twice, once I added my nutes fresh, I needed ph down and needed to chase a rising ph.
this time, when I add nutes, I get a fairly good ph, about 5.5, but it drifts down quickly to the high 4's if I let it, so Im adding ph up for the first time.

maybe it is the difference in strains, I dont know.

the only comfort is that a ph that drifts may have some merit, as different nutrients are better assimilated at different ph , so with a drift, they all get a chance.

keep chasing.

 

[MVP]

True. But then what would you do if your pH hit 7 or 8.. would you have to flush, or would you just correct the pH as soon as possible?

Depending on how old the nutes are would affect my decision. And how far along the plants are too. If the nutes are a day or two old, I would try to adjust PH. If they are a week old or more I would probably flush for 24 hours with FloraKleen, then mix nutes and refill the res after draining the FloraKleen.

 

[Spaventa]

What I would do

What I would do

Just my opinion

1. Dump whatever mess you now have in the res

2. rinse and refil with plain water

3. Adjust, gradualy to ph 5.5, adding a drop or 2 of ph- at a time and stirring and testing (with a calibrated tester)

4. Run this for a day or 2. If the ph goes beyond 5.2 - 5.8 DUMP it and repeat step 3.

5. Optional/recomended mist them in low light with Canna Rhizotonic, GT Nitrozyme or another stress releiver

6. In a day or 2 ( when the res ph becomes stable between 5.2 and 5.8, dump again, and refil resuming nutrients.

 

[Bøf]

TanzanianMagic - I think you are right. I have made a tank for mixing in the nutes and adjust the pH before I ad it to my system. I can adjust the pH to the desired level, but 24 hours later this will have increased. Then I adjust againg and 24 hours later the pH is stable. I am done with trying to get the desired pH from tabwater IN my system.. Too much trouble and concern..
-Also, your tip abut the permanent hardness of the water is F#C§ing Great! I had totally forgotten that there is something called "Carbonate hardness buffer system". Where I live we have very hard water, and the bicarbonates(HCO3-) and carbonates(CO3--) wich are present in the water are binding with the H+ added to the system, thereby buffering the pH and to a degree keeping it at the same level.. The harder the water the harder it is to adjust the pH. Now I know why people are using RO filters.. Great man

Foaf - Nice to know that I am not the only one having issues with the waterchemistry

 

[dvine]

Is it easier to maintain a good ph range if the base is RO water?

 

[JohnnyToke]

your hard water sounds like it is the cause of your high ph swings. maybe the water has ph buffers added to it and when you adjust down, its a temp fix until the buffers re-adjust it back up.

get an RO unit and i bet you will fix your ph problem. I had daily ph swings past 7.7 when I first started and once I switched to RO, the problem was fixed.

regards,
JT

 

[TanzanianMagic]

Is it easier to maintain a good ph range if the base is RO water?

Dvine,

I have tried an R/O filter, but it didn't remove the ph buffers from the water. Using a new filter, the water got as low as 4.8, but within hours, it was back to 8.3 again.

The only thing that worked (and worked on unfiltered water) is pre-ph-ing the water. And it is the simplest thing to do too, because you're already using ph-down, so now you only need to use it twice, with time in between to let the acid do it's magic. Stirring/splashing or aerating the water speeds up the process, and also gets rid of chlorene, if it's in there (some water companies now use UV light to sterilize their water supply).

 

[TanzanianMagic]

TanzanianMagic - I think you are right. I have made a tank for mixing in the nutes and adjust the pH before I ad it to my system. I can adjust the pH to the desired level, but 24 hours later this will have increased. Then I adjust againg and 24 hours later the pH is stable. I am done with trying to get the desired pH from tabwater IN my system.. Too much trouble and concern..
-Also, your tip abut the permanent hardness of the water is F#C§ing Great! I had totally forgotten that there is something called "Carbonate hardness buffer system". Where I live we have very hard water, and the bicarbonates(HCO3-) and carbonates(CO3--) wich are present in the water are binding with the H+ added to the system, thereby buffering the pH and to a degree keeping it at the same level.. The harder the water the harder it is to adjust the pH. Now I know why people are using RO filters.. Great man

Foaf - Nice to know that I am not the only one having issues with the waterchemistry

Bøf,

That's great to hear. I dropped chemistry way back in secondary school, so this waterchemistry all new to me too. The aquarium websites have a lot of useful information on water, because that is most of what they work with. It took a lot of digging, but I finally found a method that works for me.

 

[shiva das]

I stand by 5.2 - 6.0 in veg and 5.5 - 6.2 in flower, over the course of a res correctly sized for the grow.

I stand by that statment as well....the higher the ph during flowering(6.2) is for the intake of PH not N.
I use GH and don't have a problem. and I use well water that has a PPM reading at around 60.
All I do is top of with water and/or a weekened solution...the only time i had a problem with PH drift is with AN products...I will never use there base nurtients again. though I do use BB and OD with amazing results.
blessings,
shiva das

 

[shiva das]

I wouldn't PH water before adding nutrients...bad idea. I was actually just talking with someone that did just that and F'ed everything up. at the time that was the first time i ever heard anyone PHing there water before adding the nutrients...now this the second time...wow. crazy information out there. but, if it works for you...all the power to you.
blessings,
shiva das