Should i add extra magnesium to ss since i am using ro filter?

Ok so im using an ro filter. i put in extra calcium with oyster shell powder but now im thinking i might need more magnesium? Do you guys think the epsom salts i already added in will be good enough for magnesium?

Have you tested your tap water for pH and TDS? I fussed with R/O water and CaMg supplements for a year with super soil before switching back to tap water. It works great, 220ppm pH 8 out the faucet. AN pH down to 6.8-ish and it works beautiful. I give them a tsp/gal of General Organics CaMg+ and a gram of epsom salts per gallon a couple times during stretch because they hog that shit up and get mild deficiencies w/o it, even with tap water.

To be honest with ya, bro, you're going to have to supplement calcium and magnesium with your liquid feed for sure if you use R/O. Dry amendments will not break down quickly enough for the rapid growth HID's and super soil will promote. I learned this the hard way; oyster shell, dolomite, tried 'em all and ended up with horrible Ca/Mg deficiencies every time with plain R/O water. Regardless of whether you're doing organics or hydro, your water should have at least 100 elemental ppm of Calcium and 50 elemental ppm of Magnesium to keep fast growing MJ happy and deficiency-free. This means you're gonna have to add something to your water to get to these values.

You definitely don't want to use a traditional hydro supplement like Botanicare, MagiCal, SensiCal, etc. These have too much N in them for use with super soil. Our soil already has a ton of N from the blood meal and castings and needs no more, lest you risk N toxicity. That pretty much leaves us with General Organics CaMg+, which has no N and comes with a bit of molasses to help feed the micro life. Cool. The problem with GO's CaMg+ is that their ratio of Ca:Mg isn't ideal; it's too low on magnesium. We'll add some epsom salts (magnesium sulfate) to round out our CaMg profile and add a bit of sulfur to the mix, which is just fine.

Using the Cannastats nutrient calculator, I found that 8ml per gallon of GO CaMg+ should give you 125 elemental ppm of calcium and 25 elemental ppm of magnesium. Throw in a gram per gallon of epsom salts, and that gives us an additional 26 elemental ppm of magnesium and a bonus of 31 ppm sulfur. Bingo. Right on point.

If I had to use R/O again, I would use this regime all the time, using straight R/O every fourth watering or so to make sure there is no buildup of any kind. Double up on the dosage a couple times during stretch. Remember to pH between 6.5 and 7.0

Of course, you could avoid all this bullshit and just use your tap water unless it is super high out of the tap on ppm and pH, like 400+ and 8.5+. That's what I do and it works great, saves me a lot of time and grief not having to mix a feed every damn watering. The whole point of super soil, aside from super dank organics buds, is simplicity. I switched to super soil to get away from mixing a liquid feed all the time. Why the fuck would anyone want to go back to that?

Do you have at least a chlorine filter? I cant use straight tap water due to chlorine.

im not convinced that you have to add anything back to ro. i have used plain r.o, ph balanced r.o., ph balanced r.o with g.o. cal mag, straight tap water out of the wand. and de-chlorinated ph water. they all work. and ive never seen a deficiency with any.

what did your deficiencies look like jtr? maybe i was getting def and just wasn't aware.

Classic magnesium deficiency, yellowing from edges of leaves moving in eventually dying and dropping. Also calcium def. rust spots. Yield also suffered because of it. These problems went away completely when I started supplementing CaMg and then eventually switched back to tap water.

Also, my tap water has chlorine in it too. I just bubble it in a big garbage can for 24 hrs before use and it's just fine. If you're worried about chloramine, I believe there is a very easy solution as well that doesn't require filtering but it escapes me at the moment. Just do your homework on chloramine and you should find it.

interesting to be sure. i have grown some great plants in s.s. with r.o w/out supplementing cal mag. my full season 20 gallon pots did great last year and they were out for months with nothing but a light top feeding of s.s.

have u ever had good results with r.o.? or have the ladies always come up def.?

edit: i think some strains have a higher demand for cal/mag

I believe I read some where that by adding unsulfered blackstrap mollasses to your resevoir will neutralize the chlorine AND the chloramine almost immediately..........

It was ascorbic acid (vitamin C) that I was thinking of that neutralizes chloramine, though I'm unsure of how much to use.

I had great results with R/O after I started supplementing with CaMg+ and epsom salts. But straight R/O? Always deficient.