RO water and pH

[Sqwirlman]

I am currently growing in soil and I use RO water for feeding and watering my plants. Straight RO from my RO system is around 5.5 pH from what I can tell using a general hydroponics liquid drop pH tester. What I am not sure of is should I just water with straight RO and not worrry about adjusting pH or should I be adding cal mag to it then adjust the pH for watering between feeds. What I am currently doing is adding 10 drops of pH up per gallon of RO water before watering. I am currently issuing mega crop and their cal mag. I also adjust all of my feeds to a pH of 6.5 and typically feed once per week and water in between as needed. Thank you for any help you can provide.

 

[LazyNhazy]

Need more info, I run soil and ro and add a little calmag then check ph. Ro ph is incorrect until something else is added. But yes ph needs to be between 6.5-6.8 in soil everytime.

 

[bad dragon bzzz]

i thought trying to ph RO water was not possible,as there is nothing in RO water it first needs cal/mag and nutes of sorts.before you could get a ph reading ?
peeps typicaly add all the shit then ph test at the end,adjust if needed.
but i could be reading this all backwards,as ive only had 1 cuppa tea
keep er lit

 

[Sqwirlman]

When I feed my plants I do add all of the nutrients to a gallon of RO water and then check the pH and adjust the pH from there. But I only feed once per week and when they need water I have just been using RO water when my smart pots feel lite.

 

[Sqwirlman]

Need more info, I run soil and ro and add a little calmag then check ph. Ro ph is incorrect until something else is added. But yes ph needs to be between 6.5-6.8 in soil everytime.

thank your for your response. The more I was reading about RO water the less I felt confident that I was getting an accurate pH when water. I will start to add some cal mag to my RO then check the pH before watering. what do you do when it’s final flush time just before harvest. Do you just give straight RO and not worry about the pH or do you still add a little cal mag.

 

[bad dragon bzzz]

ahh so its a feed/water/feed or water/feed/water thing ? no im only on me 2nd cuppa :smoking: but me 3rd joint so im comming round a bit.

 

[Sqwirlman]

ahh so its a feed/water/feed or water/feed/water thing ? no im only on me 2nd cuppa :smoking: but me 3rd joint so im comming round a bit.

yep that’s exactly it! I usual do feed water feed. I am using 5 gallon root trapper II fabric pots and feed 1 to 1.25 gallons and water 1.5 gallons right now.

 

[Sqwirlman]

What I am wondering is for the water do I just give them straight RO at whatever pH it is or should I be adding say cal mag to it then pH it and water them. Same with the final flush the last two weeks before harvest.

 

[Sqwirlman]

yep that’s exactly it! I usual do feed water feed. I am using 5 gallon root trapper II fabric pots and feed 1 to 1.25 gallons and water 1.5 gallons right no and it’s usually every few days they need one or the other

 

[Sqwirlman]

I have all blue labs equipment. Ppm meter, ph and a soil ph probe. Is use a 50/50 mixture of Mother Earth ground swell and Mother Earth coco perlite. My soil pH is 6.5 when I test it. I have had some issue with cal mag deficiency’s and I am wondering if it’s partially related to how I water.