ph rising, help

[the green toad]

Hello to everyone,

I currently have 3 kush plants 2 weeks into flower. No matter what i seem to do the ph of my tank keeps on rising, i have done full change this morning and set the ph to 5.8, this has risen to 6.1 in only a couple of hours. The ec seems to stay stable at approx 2.0
The plants seem to be doing fine but im concerned about the constant rising ph. I have tryed topping up with 1/2 strength nutes and lower ph but it seems to rise no matter whta i do. I have included as many details as poss below, any ideas to help stabilise my ph would be most appreciated.

NFT 205 system
400w hps
plants scrogged
using ionic nutes, bloom & boost.

thanks in advance

The Green Toad!

 

[cocktail frank]

what is your medium?
did you rinse your rocks/hydroton if you are using it?

 

[MASHUP]

Hey dude, you can let that drift all the way to 7.0 on the PH scale and not see any ill effects.

I'm assuming by your EC being 2.0 they're already mature, so it's natural to see PH change more rapidly due to the water and nutrient exchange taking place.

No stress, it's just a plant.

Peace

EDIT: Also, verify the proper working order of your meters. I had a little fiasco happen over some Chinese garbage I bought. Even a paper strip test will let you know your meter is at least close.

 

[the green toad]

using rockwool blocks and soaked them before putting clones in them. ph only just become an issue seemed stable until last weeks or so.

 

[the green toad]

the plants are mature, taken as cuttings, had them vegging for couple of months, been LST them to fill the scrog screen, put them into flower approx 2 weeks ago. the nutes recommend ph 5.8 to 6.2. so is it ok to let it rise until 7.0 and then change tank or add ph adjusted water to bring back down. Gonna calibrate meters tonite and then check against test tube type kit left over from outdoor grow last year. Thanks for the advice.

 

[MASHUP]

the green toad

Did you add in another additive at the same time this PH fluctuation began taking place? Some nutes will interact with the PH constantly due to the live microbial nature.

When it comes down to it the digits are just digits. Let your plants tell you what they need.

 

[the green toad]

when they went into flower approx 2 weeks ago i used grow nutes for first week then switched to bloom, thats when the ph started to fluctuate. maybe im being too paranoid as some sort of ph swing seems to be beneficial according to advice ive read on IC forums. Whats the highest ph they can take, should i be leaving it until 7.0 or trying to adjust before this point?

 

[the green toad]

checked my meter and it seems ok, checked against ph buffer 7.0 and 4.0 and it seems spot on, also did check with test tube style kiit and this seems to agree that meter is OK.

 

[mebesideme]

I don't grow cannabis but I watch for several things to decide when to change out my nutrient resovoirs for my edibles. During heavy fruiting time I keep note of my ec, ppm and pH twice daily, and top off the level once every day with any necessary "up" or "down" in it. This helps keep the ph more consistent. I watch to see how much my ppm's go up in relation to how much the pH rises between top-off's. After a change, the pH will rise every day and the ppm's will increase too. The older the solution, the pH changes more and the ppm's don't as much. Then it gets where the ph down makes the ppm's swing and I know it's time to change.

 

[the green toad]

i check the ph and ec daily, i usually top up res most days with plain water with ph down, trying to get reservoir to go down, usually adding enough ph down in the water to get the res down to approx 5.8 ish, i am however concerned about doing this everyday and adding to much ph down to the system, am i being overcautious?

 

[thecarguy]

Green Toad-

pH going up can mean a few things. Either your plants are consuming a very high amount of nitrogen, which causes nutrient solutions to go up in pH, OR, your plants are consuming more phosphorus, and thus eating the phosphoric acid you use to bring your pH down. In any case, try a PK booster starting in week 3/4, when the plants stop using nitrogen and start budsetting. Providing them with enough PK will help regulate pH.

Keep it up.

 

[the green toad]

good news ph seems to have stabilised, thanks for all the help and advice, will keep posting as they continue to flower.