First time Hydro - Having trouble getting PH stable

[Road_Runner]

Hi guys,

I'm moving over to hydro from soil for the first time.

I've got 2 bubblers and been practising setting PH/EC etc

My bacground EC is 0.5 and the PH is 7.9

I've been making up 12 litres for a full res per bucket - then adding 10ml Canna Aqua Vega A & B, 40ml Rhizo & 8ml PH Down to make it 1.0 EC and 5.8 PH

I set the bubblers up with no plants in, then checked the levels the following day.

The EC had gone up in one to 1.4 and the other to 1.7 and the PH had gone back up to over 8!

How does this happen?

One thing I wondered is I used water straigh out of the tap, and only left the nute solution a few mins before adding PH down.

If I leave the water to stand over night, then add nutes, then adjust PH the following day, will it keep it stable?

[wert]

if your water is hard and has a high background ec it will cause problems,you can reduce the problems by leaving the water in an open container overnigh [or longer] but it will be harder to adjust [more ph adjuster] than for example water that is softer/rainwater/reverse osmosis.

[Road_Runner]

Cheers Wert,

I've set the EC on a new res and not touched PH, the water had been standing 48 hrs so I'll check tomorrow and set the PH, then check the day after and hopefully it doesn't rise as much.

If this doesn't work, my PH will be raising from 5.7 to 7.7 every day - surely that can't be good?

[high riser]

Hi road runner,
Im using same nutes at the moment My Bg ec - 0.6 Ph 7.0-7.2
Once ive added the desired amount of nutes to achieve the Ec i have to add 7 ml of Ph down to get to my desired Ph of 5.8.
Then over the course of that res i let my ec fall then add nutes back and find that this usually over a 24 hr period gives me a swing of 5.8-6.2 Ph,as i add more a+b it lowers ph back towards 5.8 and so on.
Did you have the bubblers operating in your trial run?
40 ml in 10ltr sounds a bit strong i use that in 30ltr?
Strange how the ph has risen past that what you started with

[Road_Runner]

Cheers HR,

I did do a test in the bubblers yes, in the tent with lights on.

I've noticed that Rhizotonic hardly affects EC, so although I was using 4ml per litres, it only went up 0.6 to 0.8 - it also makes the PH rise whereas the A&B make it come down!

Anyway, I set up a new res, not in the bubbler, just sat in a big 25l bucket. It had been sat for 48hrs so I added A&B only, no Rhizo and set EC to 1.0

I'll go check tonight, hopefully the EC will still be aroun 1.0 and PH won't be as high as usual due to the nutes having time to stabilise it.

My first seedling is ready do go in now so I'll just have to check EC, set PH back to 5.5 and get em going.

The problem is I can only check once a day, usually when the lights have just come one. I'm worried that I could set PH to 5.2 but by the time I get round to bring it down, it'll be at 7.2 - is that a problem?

[high riser]

Hi Rr,what sort of temps did u get in your grow area when you did your trial?
Having the res bubbling will affect the ph,had you acounted for that?
All i can say about Ph is that i was giving my girly Ec of 1.2 early on in the grow and was still trying to find the Ec sweet spot ie my ec was constantly falling over 24 hr period.
I read some canna info somewhere that recommended to run res at Ph 5.2(like i mentioned earlier i like to run Ph 5.8-6.2)So i set the new res after a drain down to 5.2 and pretty quickly she drank a lot of nutes but also showed signs of being over fertilized,so i had to bak of feed for a few days and upped Ph back to 5.8 and within a couple of days hey presto back to herself again.
so my advise is be wary of going that low.
Im sure that each plant/where its growing ie environment have a part to play in all this to.
Omha.
Peace

[high riser]

just a thought Have you calibrated your meters?

[Road_Runner]

just a thought Have you calibrated your meters?

Yeah, checked and double checked.

Even if the calibratons were out, the drift is still huge

[Road_Runner]

Hi Rr,what sort of temps did u get in your grow area when you did your trial?
Having the res bubbling will affect the ph,had you acounted for that?
All i can say about Ph is that i was giving my girly Ec of 1.2 early on in the grow and was still trying to find the Ec sweet spot ie my ec was constantly falling over 24 hr period.
I read some canna info somewhere that recommended to run res at Ph 5.2(like i mentioned earlier i like to run Ph 5.8-6.2)So i set the new res after a drain down to 5.2 and pretty quickly she drank a lot of nutes but also showed signs of being over fertilized,so i had to bak of feed for a few days and upped Ph back to 5.8 and within a couple of days hey presto back to herself again.
so my advise is be wary of going that low.
Im sure that each plant/where its growing ie environment have a part to play in all this to.
Omha.
Peace

Ok bud,

I didn wonder if the bubbles would throw PH or EC, I'll see what numbers I get from the still solution.

I would like to start my PH at 5.6-5.8 but if it's going to rise so fast, I might have to start it lower to stop it going quite so high!

I need to start one off tonight so whatever happens I'll be setting the EC to 1.0 (BG is 0.6) and then set the PH to 5.7

I'll run it until tomorrow, check and reset. The plant is only tiny so won't even be using any of the solution but I'll change it again next week.

Fingers crossed it settles down into a nice routine soon....

[Road_Runner]

Also, another question...

Any idea why when I set the PH first of all, I need like 8ml of PH down yet when it's been running fro 24 hrs, and rises back to where it was, it only needs 1-2ml to bring it down again?