Cal / Mag supplement

[johnb1963]

Hello my Friends, I was just wondering if anyone here, growing indoors in soil, and watering with tab water, uses a cal/mag supplement?

[Rwise]

With tap water there is no need for extra cal/mag, if that is a public source that is treated.

[Farmbuck]

Hi I use soil as my medium and yes I use tap water but I make sure my PH is between 6.0 -6.5. As for Cal-Mag I use it during my flowering phase.

[Woodsman67]

Have your water tested. Without knowing what minerals are already present its a guessing game. I live in Missouri. We have a well, our water is fairly high in calcium and other minerals but I still add 3 ml CalMag per gallon because the plants thrive with it. But knowing where your calcium and magnesium is to start would be ideal, then you could work off that.

[YYCannabis]

Most community water supplies will have water quality reports available online. It’s an easier way than getting your own testing done 👍

[Woodsman67]

Unless you own your water source. And that would also mean trusting the govt. Thats never a good idea 🙂

[PuravidaC]

Each municipality will have a different water hardness depending on the source. I used to grow in soil but have switched to coco. When I made the switch I started using a ca/mg supplement and started having issues with bronze spots on leaves. It happened on several grows of different strains and was getting frustrating trying to figure out what was happening. My current grow started showing the same issue so I stopped using ca/mg supplement and problem dissapeared. Ca/Mg toxicity has similar symptoms to Ca/Mg deficiency but I think I solved my problem.

[YYCannabis]

Woodsman67 I’m not an anti-gov type of person so I’ll trust the report from my local water source (what choice do i have? Trust a private company to deliver water to my door?) Anyhoo...knowing your local water supply can be beneficial whether it’s municipal supply or private well. Below is a pic of part of a 3 page water quality report for my area. I haven’t dove into the report very much, but it is quite thorough. When I used to do fish breeding as a hobby, knowing when and what the municipal water content contained was kinda important to track during seasonal changes to he H2O quality.

[Woodsman67]

Trust but verify. I think our local county extension has a free or small fee water testing program for wells. My point is, counties and municipalities test the water at the source. If you live in an older community, there could be miles of different types of pipe, and sediment, between your tap and the point of testing. Your house plumbing could be a mix of iron, lead and copper. With decades of corrosion inside. Always a good thing to have an independent water test done and not rely on govt agencies who biggest job is covering their own behinds. 🙂

[YYCannabis]

Valid point. I didn’t think about the ‘last mile’ piping.

[Cali]

Woodsman67 yup that’s true.

[ChadWestport]

I do, my tap water ppm is generally 30-50. I use small amounts of cal-mag but not in every watering.

[Cali]

ChadWestport wow that’s clean mine is around 230-300 in southern cali

[ChadWestport]

sometimes it smells a little like sulphur though...

[Ace1973]

cal/mag is something I use to balance PH as well as nutes for my plants, if you use it, you should have no problems. Just be careful as your PH can fluctuate if you use to much

[johnb1963]

i noticed black strap molasses has about the same amounts of cal & mag as the supplement, so why not save money and use molasses?
FYI, i live in socal too, the tap water sucks to drink, lol.

[Smokesteve]

Ya I use cutting edge solutions basic and I follow their feeding chart. It does incorporate a Cal/mag for every feeding so I do water/feed/ water/feed.

[grouchyoldman]

The Cal/Mag decision also seems to be strain-specific. I'm focusing on White Widow seed in living soil and that strain seems to need extra Cal/Mag throughout her cycle. A few ml/gal every other watering keeps the dreaded Brown Spots away. I haven't needed with other strains.

Just my $0.02