Quote Originally Posted by stinkyattic
If you like the idea of rain water, you GOTTA run calmag in it, then adjust the pH.
Most city water is fine for soil grows, or even hydro grows if the nute system is forgiving (canna for example- in MA and the Northeast you can get it only at the Liquid Sun shops or online). I run Canna in both my soil and hydro grows, both on city water.
Rain water, remember it has Sulfuric and Nitric acid in it from atmospheric gases. Check the EC before you decide to run it. If it has an ionic strength that even registers on a cheap probe/meter, you might want to look elsewhere, since you don't know WHERE the EC is coming from. Unknowns=problematic.
Aloha Ms. Attic

Thanks for that.

Got a question or two.
I'm using General Hydroponics grow and bloom formulas.
Figured they would supply the Ca. & Mg., no?
Label says 2.0% Calcium and .5% Magnesium.

My tap water runs 128 ppm on a TDS3 meter with a PH of 7.2
My rainwater is 26 ppm and can have very low PH. 3.9!
(Depends on the volcano and the wind.)
We get lots of sulphurous H2SO3 and Nitrous H2NO3 acid
in the rain. You can taste it
Probably Nitric and Sulphuric as well. And plenty of mineral ash.

The county water , (from wells), appears to be "over-amended" and leaves a black slimey residue when it sits for a while.
It often smells like sulphur. They claim it's clean and safe but I won't drink it. The Chloromine content has killed the guppies in my koi ponds.


Had a healthy girl on the lanai in a pot of Hydrotron.
She loved the rainwater. Was doing quite well.
We had a dry spell, I got lazy and watered her with the garden hose just twice in a row.

It got way ugly way fast. In 2/3 days she lost most her fan leaf, went yellow, then brown, then crispy/necrotic.
Flushed her with rainwater and she recovered enough to finish blooming, but lost a lot of weight. and most of her fans

So, I had just the opposite experience from Cigarettes42.
That's why I need to figure out what's going on here.
Not looking to argue, or measure dicks, just want to get better minds thinking about it.

Right now, I'm stuck with rainwater. It seems to work well, but you've got me a little worried about it.

The other question?
Is Sodium Bicorbonate unsuitable for PH up?
I test for nute strength before and after I add the Bicarb and the sodium shows up as a higher reading. About 90 ppm per 1/8 tsp per gallon.

Any advice is appreciated
Mahalo nui.
Weezard