RO water and Calmag, need advice

[Asher2019]

I am getting conflicting information about RO water. This is my first grow and Im pretty sure I killed my girls for various reasons, too much light, too little or too much nutrient, etc. I am using RO water with 0ppm and a 65/35 coco/perlite medium in a flood and drain system. I thought that with pure RO water you need to add cal mag and bring to 150ppm and then add in nutrients to bring to 300 ppm for seedlings or increase to your target ppm since there is nothing of any nutritional value in the medium. Please post your opinions as I am trying to learn as much as I can. Thanks

 

[AutoWonders]

Yes, with ro water you must add something in order to get a correct ph. Same as distilled water. I use calmag and Rhizotonic for my seedlings. I personally don't go high with ppm/ec when at the beginning seedling stage, at least until they have become somewhat established. And yes, you start the nutrient mix with additives, then add base nutes.

 

[Asher2019]

What would you say a good starting ppm is for freshly germinated seeds. My thought is to start at that number and increase 100ppm weekly until target of 1000ppm until harvest. Thoughts? And thank you for the response,

 

[AutoWonders]

What would you say a good starting ppm is for freshly germinated seeds. My thought is to start at that number and increase 100ppm weekly until target of 1000ppm until harvest. Thoughts? And thank you for the response,

I'm usually around 145 or there about's with the cal and Rhiz.

 

[BII]

I generally precharge coco/perlite with about 1/5 full dose. For example, 1 g/gallon with MegaCrop or about .5 mL/L AN pH Perfect bases nutes (with 2.5 g/L my usual max. with AN). Seems safe, not see a problem, but then many growers don't feed at all until 2 weeks or even more.

Need to add Ca/Mg as a buffer may depend on your nutes. For ex., now using MegaCrop ver.2 I've found I don't need to add any Ca/Mg during veg. growth; but I'd add maybe 1 mL/L if I were using AN or most other base nutes.

 

[Beerhunter CDN]

I use RO water with the Megacrop line of nutes and before that AN both in coco. I add Calmag in every feed but I have recently started using Megacrop 2.0 and I think it has Calmag in it in excess already. Anyway, Calmag and 1/4 strength nutes to precharge the coco. Then I feed that until the seedling is about a week old then start increasing the nute strength.

 

[Asher2019]

I appreciate all the advice, I will be planting the newly germinated seeds today or tomorrow. Hopefully this time I dont kill them. I was told I fed a Tbone steak to a baby. Practice makes perfect. Since I was a kid, I used to see pics in High Times magazine and said I've always wanted to do that. Now, hopefully with the guidance of my peers I can do that, so thank you again for the responses