I’ve always used tap water but I’d like to hear from experience as to what is the best water to use for an indoor autoflower grow…in organic soil/coco coir/pearlite (Ps I’m no chemist!)
4 Likes
From all the reading I’ve done tap water can be excellent water if it’s dechlorinated and chloramine is removed if it’s in your water and your PPM isn’t in a crazy range. Ideally Distilled or RO water is the best as it has 0 TDS 0 contaminates.
4 Likes
+1 for distilled or RO water.
3 Likes
Rain or well water for me. If not, bottled spring water. I steer away from tap water because of the additives. If I had to use it, I’d probably aerate it and treat it for chlorimide (if present).
2 Likes
I use a PUR water filter on the tap and have had zero issues. I drink water this way and it doesn’t have a chlorine or chloramine taste at all.
1 Like
Sounds like distilled is my best choice.
Less adjusting-chance fir me screwing it up…other that checking PH…should I add calc-mag or any other additives?
All autoflower indoors for the winter.
Im a rainwater guy myself! Noticable differences in pH adjusting amounts, plant ‘happiness’.
Tap water as said above could be excellent (given u remove chrlorines) since it often contains micronutes plants love. Only problem is, it often needs adjusting down into optimal pH range. And sometimes people have exceptionally hard water (horrible for ppm readers)
RO is a sound choice, I just cant get behind wasting that much water. Call me a treehugger if u want…
Distilled is a great option as well, just be ready to pay for every drop, and the plastics….
Tbh a good 5 gallon bucket or 3 can keep u supplied enough for plants unless u live somewhere notoriously dry.
3 Likes
Depends what your tap water contains. You have to have both a PH Meter and PPM meter to be able to calculate strategy for feeding events, so I would invest in one now if I was you. They both can be obtained cheaply on Amazon.
Here where I live the water is Hard. 800 ppm range at 8 PH. IF I used that on my plants they would lock out the nutes from being absorbed.
I have a 3 filter understand RO which knocks down the PPM to 50 range. I add a slight bit of crappy tap 8 Oz per gal to RO so I can get accurate PH reading.
Your readings will not be accurate if you are trying to PH water under 100 ppm as there are not enough solids in water.
Always check ph after chems to prevent this. Almost any Chem you are adding Cal Mag etc will raise that 50 PPM level high enough to obtain accurate reading. What strain of Auto are you growing?
4 Likes
Tap water guy. My PH is 7.1 with 40 PPMs. I use a nutrient line specifically for tap water. Jacks for Tap. It’s excellent and my PH after nutrients is 6.3 
2 Likes
I’ve always used my tap water in the house pulled out of a well 250’ deep. No problems
3 Likes
Amnesia Haze, Blueberry, and Northern Lights.
2 Likes
Great idea - it’s autoflower (3-6 plants at a time) indoor for the winter so the bucket is an excellent option
TY
1 Like
No problem at all. Its honestly too easy lol. The hardest part is checking for algae every few weeks. And in winter itll be even more hands off. Another issue is dry spells. A timely usage of tap water or two (with the 24 hours to sit and air out) fixes that right up
3 Likes
So you use the tap and part A? Trying to figure out which jacks bags plus Epsom salt I need, we have hard tap water and want to try jacks next grow. TIA.
1 Like
Hard hard is your tap as in your PPMs and PH? I ask because Jacks has 2 lines. 1 for optimum water, RO ect and jacks for Tap, which is what I switched to from the 321 line after doing some research. My tap is 40-50 PPMs and 7.2 PH. I definitely was missing needs minerals that the tap line provides. I can tell a big difference since the switch.
My Grow closet is small. I currently am growing 3. They are all Wedding cake. Trying to keep the tops at the same height for the lamp. Growing same strain will hopefully help me achieve that.
Will have to recheck but from memory it was around 200 ppm and 7.5 ph
1 Like
Not bad on the PH, PPMs borderline on the Jacks line. Here is the Tap and regular 321. Difference is the NPK ratio. I’ve used both and good results with the regular 321, better results with the jacks for tap, bloom and finish line for my tap water
3 Likes
I have 2 5 gallon jugs that I fill at my local health food store with RO water.
The company “Zero Water” makes really good filtration systems. My water here is a bit over 200 ppm, so nothing crazy, but the Zero Water pitcher system I have used in the past brings it down to literally 0 ppm. Obviously as the filter gets dirty it will need to be replaced eventually, but it could be a start 
Thanx, I should be about done with my nutes by next grow and want to check jacks out.
1 Like