29 replies to this topic

[GreenDreamz]

I have a Reverse Osmosis system hooked up with 0 ppm coming out. I am going to run the Lucas method dwc totes. Do I add Cal/Mag or somethig to the water? I heard somewhere you can add 10% tap water to your res and it will eliminate the need for cal/mag. My tap water is like 480ppm and 7.8 ph would it even be safe to mix?

[Romen]

I have a Reverse Osmosis system hooked up with 0 ppm coming out. I am going to run the Lucas method dwc totes. Do I add Cal/Mag or somethig to the water? I heard somewhere you can add 10% tap water to your res and it will eliminate the need for cal/mag. My tap water is like 480ppm and 7.8 ph would it even be safe to mix?

I use r/o and add cal/mag to get my ppm at about 150-200. Most nutes are designed for tap and assume some pre-existing minerals.R/O removes everything the good and the bad , so then you replace with good cal/mag.I'm sure this is but one of many suggestions you may get, but this is my experience.

[ToadInCan]

I have a Reverse Osmosis system hooked up with 0 ppm coming out. I am going to run the Lucas method dwc totes. Do I add Cal/Mag or somethig to the water? I heard somewhere you can add 10% tap water to your res and it will eliminate the need for cal/mag. My tap water is like 480ppm and 7.8 ph would it even be safe to mix?

I am also running DWC totes, and using the Lucas formula nutes. This is just my own observation, but I think that it's all in there. I mean all the cal/mag that the plant needs is in the Lucas nutes. I experienced a cal/mag deficiency early on, and picked up some Calmag Plus. After mixing it in and waiting a day or two, I wasn't noticing any improvement. What I did discover was that my pH had gotten way out of spec. I've learned that keeping the pH right is very important. If the nutrient solution is too acidic, or too alkali, then the roots won't take up what the plant needs. I keep my pH at just below 6, and I havent touched that $20 bottle of cal/mag in months. Just sharing what I've learned... I wish you good luck!

[Honeyoil]

The lucas formula is designed to be used with RO water. You do not need to add anything else, unless you are growing in coco. lucas formula That being said, some strains may require additional nutes to be added if your plants show signs of deficiency. I would not start with any other additives. You probably won't need any.

Edited by wclark, 24 April 2011 - 08:40 PM.

[GreenDreamz]

Thanks alot you guys are awesome!!

[GreenDreamz]

Well my i developed a calcium def by not using calmag in my water. how much do i use per gallon for dwc?

[Honeyoil]

2.5 ml per gallon

[anonymousgrower?]

Romen hit it on the nose!

Start at 0ppm with r/o bring it up to 200ppm with your cal mag additive

[LongHairBri]

I like MagPro from DynaGrow. it has ALL the trace elements/nutes in it. I use it from rooted clone to finish @ 5ml. per gal

[Romen]

I think LongHairBri's choice is the best , Mag Pro is a better choice, most nutes have cal , too much calcium nitrate can muck things up. Mag seems to be the lagging mineral. are you using R/O?

Edited by Romen, 18 June 2011 - 10:38 AM.

[I*M*Lady*Zandra]

We've Run DWC for Years..
IMO- If using RO water, using Super Cal-Mag, Micro -blast etc.. and Silica would really help- but watch your EC!
You want to add your nutes 1st-- check the e/c then add the added micros in SMALL amounts-- not full doses-- to reach your ec!!

[LongHairBri]

I use the Lucas method. I fill res, check ppm. adjust to 1000 ppm. add half as much cal/mg as nutes

[purklize]

I use 7ml of Botanicare Calmag for every 3.5 gallons of water, which is how much is in my bucket when I fill it up to the bottom of my 6" net pot lid. Puts the ppm squarely at 150 and the plants seem happy.

[Inepsa]

Does the mag pro not have calcium in it? I use botanicare cal-mag plus and it gives most of my plants too much calcium and Nitrogen.

[donnachris]

I am also running DWC totes, and using the Lucas formula nutes. This is just my own observation, but I think that it's all in there. I mean all the cal/mag that the plant needs is in the Lucas nutes. I experienced a cal/mag deficiency early on, and picked up some Calmag Plus. After mixing it in and waiting a day or two, I wasn't noticing any improvement. What I did discover was that my pH had gotten way out of spec. I've learned that keeping the pH right is very important. If the nutrient solution is too acidic, or too alkali, then the roots won't take up what the plant needs. I keep my pH at just below 6, and I havent touched that $20 bottle of cal/mag in months. Just sharing what I've learned... I wish you good luck!

What kinda of ph problems did you have. I am in ProMix and am having some serious downward drift of my ph. Downward to something like 5.4 and in promix is should be right around 6.5. I dont know why it is doing it but can someone please help me out???

[Kingdiamond]

I used to use an ro system and had nothing but probloms with it i went back to straight tap and ph up my plants have never looked healthier.

[mike44]

Below is a typical analysis of my tap water. Most of the contents are actualy good for the plants. Some or all of the first 4 items can actualy act as a buffer to stabilize the ph, even if it is adjusted. With R/O water all these chemicals are taken out, and this will contribute to your PH fluctuating the way it is. Letting this tap water sit for 24-48 hours will remove the chloramine which is toxic to plants. There are 2 or 3 other undesireable components which can be partialy removed with a carbon filter. All in all I would prefer to use this water over R/O water when I am growing in soil. Otherwise, it becomes neccesary to add the chemicals back that you have removed with R/O. If you don't, your PH can fluctuate like yours is doing, and also the plants can be deprived of nutrients neccesary for proper growth. I only use R/O water in my bubble buckets, as the results I have gotten using R/O in soil have been less than spectacular. Why spend so much extra time and money adding back minerals that are there in the first place? Try using your tap water instead of R/O and you may find your PH becomes much more stable. Or you can add back the Calcium and Magnesium you have filtered out and this will help too.


Analyte Reported as mg/l
(except as noted) Typical
Concentration
Range
Calcium CaCO3 50 40-60
Magnesium CaCO3 40 30-40
Total Hardness* CaCO3 90 85-100
Carbonate (CO3) CaCO3 20 15-30
Bicarbonate (HCO3) CaCO3 15 10-25
Total alkalinity CaCO3 35 25-60
Sodium* Na 44 30-60
Iron* Fe 0.2 0.1-0.5
Sulfate* SO4 70 40-150
Chloride* Cl 46 10-100
Silica* SiO2 10 9-14
Fluoride F 1.2 0.6-1.4
Phosphate, Tot P 0.8 0.2-1.0
Phosphate, Ortho P 0.2 0.1-0.5
Chloramine Cl2 (at plant tap) 2.0 1.0-3.5
pH pH units 9.4 9.2-9.8
Turbidity NTU 0.2 NTU 0.1-0.5
Conductivity* uS/cm 350 250-750

[abe supercro]

Most people use RO water because they have well water. I'll be going back to adding a small percentage of well water to my mainly RO reservoir, as well as some Cal Mag.

[purklize]

Tap doesn't always work... I live in an old building, my tap water kills plants... I always wondered why my houseplants went downhill so fast, turns out that was it. The pH is around 9, the ppm around 300, and it's probably loaded with copper and other crap, not to mention it's not sterile and probably loaded with crap that could infect the roots...

[GanjaWarrior]

um....hmm....tap....no way. lucas was intended to be run with ro....and for anyone else no way. Univ of Wis study showed high phos plants could receive as much as 70 percent of their phos uptake from beneficial fungus in soil... the same kind that tap water kills. ro is the way for lucas, if u grow soil and insist on using tap water, grow in soilless ur killing all the good things in ur soil.