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New grower - Need help picking a water source

proteasome

New Member
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.
 

Scientific

New Member
Hi p-some,

1. One of the name brand fertilizer providers (it's Advanced Nutrients, if memory serves) makes a hard water formulation. Take a look.

2. Ion exchange units that use NaCl are a no go in my opinion. Too much Na.

3. USE THIS WATER IDIOT! ;) Seriously, it's rain water being used to water a weed, right? If you're worried about the schmutz, then you could do a course prefilter first--I'm talking about using a kitchen strainer, but even that's probably over kill. (But I guess I would.)

4. Distilled? Too expensive. How about just taking gallon jugs to WalMart or wherever and filling 'em with reverse osmosis water?

One more thought from a guy who had SoCal water similar to yours: You can probably cut the softer water with some of your hard water and get a free Ca boost. That would probably take a little experimentation, but maybe mix your soft and hard to get the same PPMs as when using a commercial Ca/Mg supplement at 2.5 ml/gallon. (Sorry, can't recall what that PPM is.)

Sounds like you're doing your homework. Success is assured! ;)
 

proteasome

New Member
THANK you for the reply! I've been trying to get help with this for a while now. My rain barrel is, as I said, not well maintained. You don't think that I'll need to do extensive multi-step filtering to clean my water? I'm worried about having to try and filter bacteria or other micron-sized particles, or sediment from animal droppings. It wouldn't worry me as much if I were growing outside, or not using coco, but I've been reading about how important water quality (not just pH or cal/mag) is important when you're not using soil.
 

Scientific

New Member
"Water quality" is important mostly as regards not having too much mineral content or the wrong mineral content. "Animal droppings" have another name: "fertilizer." ;) And no matter what you do, you're going to have bacteria, viruses, fungi, protozoa, "micron-size" and bigger particles... Again, it's a weed, and weeds have been growing with all that in their water for a billion years. Seriously, not to worry.
 

BudBoy2

Well-Known Member
THANK you for the reply! I've been trying to get help with this for a while now. My rain barrel is, as I said, not well maintained. You don't think that I'll need to do extensive multi-step filtering to clean my water? I'm worried about having to try and filter bacteria or other micron-sized particles, or sediment from animal droppings. It wouldn't worry me as much if I were growing outside, or not using coco, but I've been reading about how important water quality (not just pH or cal/mag) is important when you're not using soil.
I've been using rain water all summer long and no problems. I just use ph water once a week with nutes added. But I'm like scientific, bottled water is just fine as is rain water. Keep collecting it bro it's free and does work. Good luck!..✌
 

Scientific

New Member
One thing I remember reading about using rainwater is that if you're close to a major source of air pollution (busy highway, smokestacks), that that can end up in your water, which is not so great. But that was for drinking water...
 

Scientific

New Member
Cococoir/perlite home-blend medium. Plan to hand water and drain as necessary w/pH and cal/mag adjusted water.
Have a look at the coco grow in my sig file, especially the link to the YouTube video there about how to do drain-to-waste coco. In a nutshell, water with nutes to 10% or so runoff every day.
 

CuiBono

New Member
I grow with tap pH 6.8 and ppms 200 - 240 source
Drain to waste
Canna Coco A&B
Cannazym
Calmag plus
After mixing pH 5.8 ppms 700 - 750
 
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