Ideal Ph for Promix

[COflower]

I am using Promix and am trying to figure out what the ideal ph of this SOILLESS mix should be. I know SOIL should be 6.5-7 for Cannabis, but am wondering since it is a soilless mix if the ph should be lower….
Some people say that promix does not need to be ph adjusted with dolomite lime. What are everyones thoughts on that?

Thanks a lot for any help

 

[GrowersWarehouse]

I never added any lime and I had great results with pro-mix. I generally pH my nutrient mix at 5.8. I water 5 gallon pots about twice a week and give them about 3/4 of a gallon each. Try Canna Terra nutrients on it, easy to use and phenomenal results!!!

 

[COflower]

I have the Substra Canna nutrients and all of the additives. Have you ever used these nutes?

I never added any lime and I had great results with pro-mix. I generally pH my nutrient mix at 5.8. I water 5 gallon pots about twice a week and give them about 3/4 of a gallon each. Try Canna Terra nutrients on it, easy to use and phenomenal results!!!

 

[a mongo frog]

I never added any lime and I had great results with pro-mix. I generally pH my nutrient mix at 5.8. I water 5 gallon pots about twice a week and give them about 3/4 of a gallon each. Try Canna Terra nutrients on it, easy to use and phenomenal results!!!

Do u think 3/4 of a gallon is too much water for a 5 gallon pot in a peat based soilless? 2 waterings a week just sounds like not enough feedings per week. IMO as much feedings as u can per week is the key to soilless grows. I also think 5.9-6.3 is the ph range.

 

[TN Jedeye]

I never added any lime and I had great results with pro-mix. I generally pH my nutrient mix at 5.8. I water 5 gallon pots about twice a week and give them about 3/4 of a gallon each. Try Canna Terra nutrients on it, easy to use and phenomenal results!!!

I use Pure Blend Pro, adjust to around 5.8-5.9, and have never added lime. I love pro mix.

 

[cannabineer]

I used ProMix on my last run. I had best results at six point two. Nirvana White Widow

 

[TN Jedeye]

Water them when they're thirsty.... when the containers get light, water them.

 

[cannabineer]

Do u think 3/4 of a gallon is too much water for a 5 gallon pot in a peat based soilless? 2 waterings a week just sounds like not enough feedings per week. IMO as much feedings as u can per week is the key to soilless grows. I also think 5.9-6.3 is the ph range.

I watered "until runoff" and in two 7-gallon pots and two 4-galloners in flower. The plants started wanting it every 4 days and then going to every day as they gained size. Those four pots would want 8 gallons divvied up between'em for every watering session. I used my own salt fert formula at 450-550 ppm; this was the best balance between their nute and water uptakes. They got pretty greedy when they got big, but didn't like any bump-up in ppm.

 

[COflower]

My tap water is about 7.3 ph. Should i adjust the water/nutrient solution to 6.4 before applying to premix which i believe has a 7 ph out of the bag? Remember, i am using chemical fertilizers (CANNA) if that changes anything.

 

[cannabineer]

My tap water is about 7.3 ph. Should i adjust the water/nutrient solution to 6.4 before applying to premix which i believe has a 7 ph out of the bag? Remember, i am using chemical fertilizers (CANNA) if that changes anything.

Definitely adjust pH before application. The pH "out of the bag" isn't fixed since every supply of water has its own ion/buffer strength. In fact, if your water is rich in bicarbonate, expect the pH to rise upon standing as carbonic acid decomposes and blows off. Recheck in a day if you're storing a batch for more than one watering.
What is your tap water's TDS?

 

[COflower]

Its crazy how much conflicting information there is online. I see threads where a lot of people say ABSOLUTELY add some dolomite lime to the promix bx because there is not enough in there

 

[cannabineer]

Its crazy how much conflicting information there is online. I see threads where a lot of people say ABSOLUTELY add some dolomite lime to the premix bx because there is not enough in there

It all depends on how one feeds. I added zero dolomite and just minded the pH of my solution. I used a formula already rich in cal and mag.

 

[COflower]

The ppm of TDS in my water is only 44 so i am definitely on the soft side. I purchased CAL+MAG+IRON to add to my water. So 6.4 is a good reference for adding my nutes straight to the Promix BX mixed with 15% perlite?

Really appreciate the help

Definitely adjust pH before application. The pH "out of the bag" isn't fixed since every supply of water has its own ion/buffer strength. In fact, if your water is rich in bicarbonate, expect the pH to rise upon standing as carbonic acid decomposes and blows off. Recheck in a day if you're storing a batch for more than one watering.
What is your tap water's TDS?

 

[cannabineer]

The ppm of TDS in my water is only 44 so i am definitely on the soft side. I purchased CAL+MAG+IRON to add to my water. So 6.4 is a good reference for adding my nutes straight to the Promix BX mixed with 15% perlite?

Really appreciate the help

In my subjective opinion 6.4 is a bit on the "sweet" (high-pH) side. Six even is a good mark, and 6.2 is also proven ...