I need help with tap water and nutrients!

I’m trying to work through my first DWC set up and grow. It’s been harder than I’d hoped. All of my little ones are yellowing from the tips of the leaves inwards, starting from the bottom. Then they all started drooping and looking pretty pathetic.
I use tap water and PPMs are 285. I know that’s not too hard. But I really think that a lot of that is calcium. I think I read that a part of our problem is we have very Alkaline water and get a lot of build up. I asked my husband for a RO system for my birthday so we will see I guess. Lol!!
So I got the GH Flora series for hard water that I’ve been using. I’ve done a little calmag foliar here and there too. I ordered a few extra products after doing a little research. So once that delivers I will have the Flora trio, hydroguard, armor si, rapid start, florablend, and diamond nectar. My thinking is that with those I can get a better nutrient uptake even with the large molecular structure of the tap minerals.
Does anybody have any advice or tips for a total pathetic newb? Lol I hope that getting the nutrients lined out will help a lot. I have a 300 watt galaxy hydro LED and 2 300 watt Mars hydros. I use the closet under my basement stairs and currently have it set up in the shorter 4 x 4 area. The temps are 75 to 77 during the day at 66-68 at night. Water temps have stayed below 70, normal is 68.


@ktreez420 or @Donaldj are two hydro growers hope they see the tags and can square you up I’m a soil guy so I won’t be much help in you DWC set up @Tping212
Welcome to the forum you’ll get all the help you need here you can to the right place :+1:
Happy growing :v:CB


Here is a really good deal on a pretty good R/O system:


It isn’t “larger molecular structure” as much as it will cause your pH to climb to above ideal, and for DWC 5.8 pH is ideal, avoid higher than 6.1 and avoid lower than 5.5 pH. Bad pH will change the availability of the nutrients to be taken in by the roots, this is more of a molecular electrical action than “size”, and it has to do with ions and anions at the chemical molecular level.

happy growing,


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Oh really? Dang yeah that’s just something I read. That the molecules from the tap are too large to actually be absorbed and that amino acids might help.

Thanks. I appreciate it. I have 2 soil plants going but they aren’t giving me hell right now. Lol

Well if you need help with them just tag me MacGyverStoner is also a good reference haven’t seen him around much but he posted some good info for you
Just put @ symbol in front of my user name and I’ll be notified when you post a question to me
Happy growing brother @Tping212

Again, not too large, but the wrong composition to be used or taken in by the roots.

Proper pH can “break down” the molecule, not necessarily into smaller molecules, but at the correct pH – break apart, say – the calcium carbonate – CaCO3, and recombine it with the nitrogen in your nutrient formula to create calcium nitrate – Ca(NO3)2, which is highly useful and absorbable to the plant’s roots at the proper pH.

The above description is overly simplified, but should give you a better and more accurate idea of how things work.

Another maybe more accurate example would be when you use the phosphoric acid – H3PO4, that is generally the main ingredient in most “pH Down” formulas to bring your tap water’s pH down, and this breaks the calcium carbonate – CaCO3, and the phosphorous recombines with the calcium to make calcium phosphate – Ca3(PO4)2, and again a highly useful and needed compound supplying both calcium and phosphorus for the plant.

Happy growing,


That’s very useful information. Thanks. I wasn’t trying to be argumentative, just elaborating on what I had “learned”.

I didn’t think you were argumentative. I was just trying to help educate and clarify the information, lol.

And you are very welcome.

Happy growing,


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