Tap Water............

My current tap water is:

480 ppm
6.9-7.1 ph



Is this safe for DWC?

I don't wanna fork out the dough for a RO system RIGHT NOW. In the future, it is in the plans, but right now, I am just trying to get by.

I have all my lighting, and every part I can think of for a successful grow... and currently using bottled water, but it is getting pricey... @ about $15/ every two weeks.

So, I wanna know, if I leave the water out for 24-48 hrs, will it be safe, or should I just stick to bottled water.


Also, what about mixing half bottled water/ half tap water?

Water filters are cheap and Ph down is even cheaper. Once you filter it, lower the PH and age it, it should be fine. I've been using aged tap water on my plants for years and they grow like crazy.

tap water is cool.I've always used it and never had a problem.I sit it out in a open container for at least a day.

Awesome guys, thanks for the heads up.

What I am more concerned with is the PPM of the water.


being that it is around 480ppm...
do I need to compensate when adding nutes?
Or use the current strength + the 480 ppm tap water.... or use the current strength, but subtract it the 480ppm?


Thanks all!

it all depends on the nutes. with high ppm tapwater normal folk worry about the cal mag levels in the water. Hydro nutes should have some concentration of those minerals.

You have hardwater. I do to. Normal hydro nutes will overpower your plants. So I use gh three part with hardwater micro and with my hardwater it works perfectly. It also has buffers to remove any ph imbalance that tapwater will cause.

This stuff works like a charm.

If anybody is interested in learning more about water and different purification methods, click on the link in my sig.

My experience
bottled water=worked great
filtered water=worked great
water sat out=worked great
straight from tap=worked great

The city water in my area is close to your, maybe a little less ppm, ive started using my water straight from the tap, in ORGANIC aero and ORGANIC soil, never had a problem with either from chlorine. I would just experiment, try straight tap if things start looking bad switch back to bottled and invest in r/o.

Makes me realize how lucky I am to have water coming out of my tap at 140-170 ppm!!!

DivinePower said:

Makes me realize how lucky I am to have water coming out of my tap at 140-170 ppm!!!

Click to expand...

That's just about perfect! You are lucky indeed!

What is the ideal ppm for water??

Ideal PPM for tap water is 0 - 300. 450 has a ton of impurities! It's almost thresh hold. 500 and above is REAL HARD / Bad water. If your water is that high in PPM out of faucet I would almost want to boil the water a day before I use it. Make sure you add some H202 to kill bacteria. Also you can try buying a Zero Water purifier container or invest in an RO unit for your house drinking water. 450+ = no bueno!

my tapwater is over 700 ppm. I grow fine with it so far. Something is always a lttle off. I used an ro filter and it was still 400 or so ppm! it was a cheap filter. But I did make compost tea with it. This run with just tapwater and hardwater nutes is my best yet. Amzing growth.

My tap water is 920 ppm and around 7.3 pH. I couldn't get myself to use it so, I started using Culligan water there for a while in the 5 gallon water cooler bottles but that was starting to get expensive too at 5.00 bucks a bottle. I wanted to buy a RO filter but my water pressure is only 35 psi and that's to low for an RO filter to work properly. So I got a water distiller off eBay for 120.00 shipping included. It makes 1 gallon of distilled water an hour. I only have a 5 gallon res and I've been going through 10 gallons a week so it only take me 2 days to make a weeks worth of water. After I'm done distilling my 920 ppm tap water I end up with 10 ppm and my pH is 6.0. I would recommend one to anybody that has a smaller res and doesn't want to pay high dollar for an RO filter. I have pics of it in action and all the nasty stuff that it leaves behind if anybody want's to see.

filling res is my worst task. I am so lazy after I get off work. I am setting up 8 dwc five gallons. They are a two month veg and two month flower. perpetual. So I would need 8-16 gallons a day in the end. I am having a pain with one in flower and a few in veg right now. Thank god for tapwater this time as i have done it with the slow as ro machines and always had to run out at the last minute to the store. On top of that previously I hated cal mag.

If I dont get tapwater results this time around that I want then I wil consider switching again as my ppm pen is a hardy thing and that should make cal mag and ro or distill easier.

Until then gh hardwater micro is the only way I can think of to do it with hardwater.