RO Vs. Distilled Water
- Thread starter Cugine
- Start date
Al B. Fuct
once had a dog named
Roseman is right, as usual. Very hard (lots of dissolved minerals, usually limestone) tap water will cause the tank pH to jump up when mixing up a fresh tank or adding water in between tank dumps. You can correct your pH downward with "pHDown" solutions.
RO or distilled water, while nice, isn't all that necessary. I've been running tapwater for the last 10 years. Just have to adjust the tank pH downward after topping up with plain water.
pHDown comes in two flavours; a phosphoric acid based solution for use in flowering (the plants love the extra phosphorus) and a nitric acid based pHDown for vegging plants (breaks down into nitrogen). pHDown is one of the very cheapest solutions you'll buy from a hydro shop. May be available at some discount or hardware stores these days, too.
My dehumidifier puts out about 10 litres of totally mineral and chlorine-free distilled water per day. I sure don't pour the stuff out! It gets recycled back into the res tanks.
Incidentally, chlorine in tapwater won't hurt your plants one bit. If anything, chlorinated water is your friend. It will suppress pathogen growth in your nutrient solution. The chlorine evaporates from open containers of water in about 24 hours, so that's about how long the tank's protection from rampant pathogen growth lasts without your help.
After the chlorine is evaporated, you have to suppress pathogens yourself. I use hydrogen peroxide (H2O2), 50% horticultural grade, at 1ml/litre of tank volume every 3-4 days. Don't use H2O2 with organic nutes.
RO or distilled water, while nice, isn't all that necessary. I've been running tapwater for the last 10 years. Just have to adjust the tank pH downward after topping up with plain water.
pHDown comes in two flavours; a phosphoric acid based solution for use in flowering (the plants love the extra phosphorus) and a nitric acid based pHDown for vegging plants (breaks down into nitrogen). pHDown is one of the very cheapest solutions you'll buy from a hydro shop. May be available at some discount or hardware stores these days, too.
My dehumidifier puts out about 10 litres of totally mineral and chlorine-free distilled water per day. I sure don't pour the stuff out! It gets recycled back into the res tanks.
Incidentally, chlorine in tapwater won't hurt your plants one bit. If anything, chlorinated water is your friend. It will suppress pathogen growth in your nutrient solution. The chlorine evaporates from open containers of water in about 24 hours, so that's about how long the tank's protection from rampant pathogen growth lasts without your help.
After the chlorine is evaporated, you have to suppress pathogens yourself. I use hydrogen peroxide (H2O2), 50% horticultural grade, at 1ml/litre of tank volume every 3-4 days. Don't use H2O2 with organic nutes.
VictorVIcious
Well-Known Member
I look at it a little different. I figured I had a choice. Spend $150.00 for the Bluelab ph meter or spend $220.00 for a RO system. Guess which one I choose. The difference in the cleanliness of all of the equipment makes mine the wise choice. Of course my tap water is from a well. In case anyone wonders my system can produce 85 gallons of RO water per day in the winter time. When the weather warms up it will produce more. VV
I use hard tap water (pH 8.8, add pH down, and don't have any problems. Even w/ dH2o the pH has to be brought down a little as ~5.7 is the ideal. However, I'm thinking quite seriously about investing in a RO sys - for my plants and also for myself. Vic, which system are you using?
VictorVIcious
Well-Known Member
I have a Spectra Pure dual membrane model. Installation was easy. You do need a drain available since there is about a 5 to 1 ratio for waste. I just added some more 1/4" line and tapped into the side of my sewer line. Took less than an hour to install. VV
Al B. Fuct
once had a dog named
VV, that's got to make nice drinking water.
If my tapwater had much more minerals than it does- and it clocks a pH8.7 most days- I'd think about an RO system like yours.
I can corroborate ropascope's experience; the water that comes out of my dehumidifier is about pH7.2. Still has to be corrected down, but not as much as my tapwater.
If my tapwater had much more minerals than it does- and it clocks a pH8.7 most days- I'd think about an RO system like yours.
I can corroborate ropascope's experience; the water that comes out of my dehumidifier is about pH7.2. Still has to be corrected down, but not as much as my tapwater.
VictorVIcious
Well-Known Member
I think I know what you mean. I have a book, Integral Hydroponics written by an Aussie and he has a section dealing with 'perth' water. Kinda skipped that section. You probably know what he is talking about. VV
Al B. Fuct
once had a dog named
Perth hasn't much water and what they do have from natural sources isn't so great. Perth is so dry they've had to put in a desalination plant to convert seawater. I'd think this would be a boon to Perth indoor growers as desal water is so rigorously quality controlled.
The writer was complaining about relatively high salinity even in river and bore water. Bore water from anywhere is of course chockers full of minerals and metals like iron.
GangAman420
Active Member
hey guys... i've just gone through all this myself just recently...
i'm running a drip hydro system, and for my first run with it i used regular tap water... it was a mistake for me. i live in southern california, and the issue i was running into was not so much the ph count but the ppm. there's a lot of junk in tap water. my water was coming out to 360 ppm. i initially bought a britta jug system, but that has an active carbon filter and it only took the ppm down to 240. I finally bought a RO system from costco, and i love it. my water comes out at 40 ppm exactly everytime and it tastes great for me!! i highly recommend it! At costco it was cheap, got mine for 160 plus tax. good luck!! roll it up and burn it up!!
i'm running a drip hydro system, and for my first run with it i used regular tap water... it was a mistake for me. i live in southern california, and the issue i was running into was not so much the ph count but the ppm. there's a lot of junk in tap water. my water was coming out to 360 ppm. i initially bought a britta jug system, but that has an active carbon filter and it only took the ppm down to 240. I finally bought a RO system from costco, and i love it. my water comes out at 40 ppm exactly everytime and it tastes great for me!! i highly recommend it! At costco it was cheap, got mine for 160 plus tax. good luck!! roll it up and burn it up!!
Al B. Fuct
once had a dog named
I could see a real advantage for RO in a drip system or any other sort that has small sprayer apertures. Anything that reduces mineral content that much would reduce clogging probs.