RO/DI Water Users - Step inside PLEASE

I would like to hear from those who use RO/DI water for there plants. I think it has been causing my problems. I know I will need to add some Cal/Mag+, but not sure how much and how often to use it. Will I still need to add the cal/mag when mixing nutrients? Anything else you can add about the subject would be great.

I use only RO. Yes it lacks calcium and Mg, also Iron, and yes you will have to supplement at given times. When to feed a cal/mg supplement varies from medium to medium. Growing in soil you wont have to add as much, in coco you will have to add a bit more, and running a hydro setup you will need it in your res all the time (with certain exceptions). Also remember there are nutrient lines out there designed for non RO users with hard water, I cant comment on them cause I havnt used them. There are also nutrient lines with higher CA, Mg and Iron levels in mind, you may want to check those out.

The basic reseach on calcium shows that in a plant its no different then a human, We need Ca in the beginning of our lives and close to the end of our life cycle.

I am going to grow in FFOF and will be using Grow Big and Big Bloom. Is there a ppm I should be shooting for when mixing the cal/mag+?

no there isnt a ppm to shoot for as your not running hydro. Cal/mag+, calls for 5ml per gallon in container gardens. The only time you will have to break out cal/mg+ when running in FFOF will be late flower, If at all.

FFof comes with abundant amounts of nutrients in it, They start to deplete after the first couple weeks though.

Grow big is for veg, Big bloom is just an all around nutrient supplement in itself, you didnt mention Tiger bloom though, What do you intend on feeding in flower. Also with that Fox farm trio, its doubtful you will need calmag +, seeing as (althogh I dont have a bottle handy so dont quote me) it has trace minerals and calcium and iron.

Opps, your right, Tiger Bloom is what i'll be using, not the Big Blossom. I don't see anyone really using RO/DI water, just RO and wondering if maybe the DI step is doing something weird to the water.

Both methods are used to remove dissolved solids (ions) from water. In basic terms, the distillation process boils the water in a still, and the steam is condensed out and collected. Any of the non-volatile components that were in the water are left behind, so you end up with water whose mineral content is usually less than 10 ppm.

RO forces water through a filtering membrane. The pores in the membrane are small enough to filter out a lot of the molecules that make up dissolved minerals, but it can't filter out all of them.

Id say first before you look into purchasing a RO unit, to test your water to see how high the ppm's are. I've lived all around the US. Ive seen 80ppm from a tap and I've seen 425ish from a tap, and everything in between. I grew in ffof using the nutrient trio with tap water at 200ppm....everything was smooth as butter.

I just checked my tap water (hard water, no softener) and the TDS is right about 425 with a pH of about 8.2. I already have a RO/DI unit, and that comes out at a TDS of 4 (need to change the filters). I will get 0 TDS after I change the DI resin. I don't know if you are thinking the DI stands for distilled, but it is de-ionization, not sure how much of a difference that makes. Perhaps i'd be better off splitting into the line before the DI resin and using just RO water?

Took this little ditty about DI:
"DI uses ion exchange resins, which exchange the ions in the water, such as iron, magnesium, copper for hydrogen and nitrate, sulphate, phosphate for hydroxide. DI is fine to use, and if done correctly is better quality than a straight RO system (without a DI on the end)."