Choosing the best water source for coco

Discussion in 'Coco Coir' started by schismatic_jukebox, Aug 23, 2017.

  1. I've been reading as much as possible about water and I'm looking for advice on whether there's any way I can use one of my existing water resources without having to invest $200 in RO. I have a background in lab science, but I'm still a bit overwhelmed by conflicting information.

    My Grow (first time): 5xNL autoflowers under 400 W dimable MH/HPS, air-cooled-glass-enclosed ballast, w/in-line exhaust fan/carbon filter in 2x4x7 tent. Cococoir/perlite home-blend medium. Plan to hand water and drain as necessary w/pH and cal/mag adjusted water.

    If anyone has comments on my general setup I'd welcome it, but I'm most concerned about getting my water right. Here are my (non-RO) options.

    1) Un-softened municipal tap water. Our water is Very hard (18.1 grains). I've read on these forums that it's difficult to properly pH adjust water that's this hard (because of the carbonate buffer?), and the replies with the most up-votes say "save yourself the trouble and invest in RO." Does anyone know if it's possible to do a coco grow with water this hard successfully? I know I won't need cal/mag supplement, but I've been reading about more problems than successes with muni water this hard.

    2) Softened water. We have a household water softener. I've read that this water isn't suitable because it's too high in Na, and this will cause alkalinity problems at the root tips. I've kind of written this off as a valid option, but if anyone knows how to grow with softened water you'd be my hero.

    3) Rain water. We collect rain water runoff from the roof/gutter to use for watering outdoor plants. I know what you're thinking at this point: USE THIS WATER IDIOT! Here's my concern. I didn't put any measures in place to pre-filter this water at all, so it contains everything from plant liter to mosquito eggs to viruses. From what I've read (please correct this if I'm wrong), the fact that this water is so raw means that I'll need to use a multi-step filtering process, and getting enough of it to use for my grow could be almost as expensive as setting up RO. I hope I'm wrong about this and somebody knows a cheap way to make my dirty-ass rain water usable for my setup.

    4) Buying distilled water. My least favorite option, but possibly the best? This is my first grow, and the fewer factors I have to worry about the better. Buying bulk distilled water seems like it would cost $50 - $100 for this grow (ouch!) based on the machines I've seen at supermarkets, although I don't know how much water the plants are going to use. Since I'm not yet committed to multiple grows (i.e. I'm too cheap to buy RO machine yet) this doesn't seem TOTALLY unreasonable, but it would be logistically difficult to transport the water at the peak of flowering.

    So. If you made it this far thank you very much for reading my complete newb water freak-out. I feel stuck with my grow until I can figure this out.
  2. Softened water is out because of the salt.
    I'd personally not use the roof water.
    Buying water, after a while you could have just bought RO filter system...
    Thus I'd personally use tap water until you can get a RO system.
  3. I can't comment on your tap water but I would use it and see if a problem occurs. You can always change to r/o or do a half and half with your tap water if you need to. I grow in coco and have been using tap water for years with no problems and no need for calmag - maybe I'm just lucky. Good luck.
  4. I used the water from the dehumidifier and supplemented with rainwater collected from the roof downspouts. No problems that I know of. My tap water is from a well and has lots of manganese and iron with a high pH. This was causing problems for my plants until I switched.

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