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Illusion
10-19-2007, 08:27 PM
Something I haven't been able to figure out is...

Lets say PPM of tap water is 200, vs RO water which could be 50...

if wanted my PPM to be 400 for my reservoir, and Im using tap water with a base of 200 already, Then I would only be able to put as much nutrients in to make it 400, right? But if i was using water if a base of 50 PPM, then I would have 150 extra PPM of nutrients?

So does it slow down growth by using water with a high base PPM since you can't add as much nutrients? or does it really not matter...

the image reaper
10-20-2007, 02:31 PM
Something I haven't been able to figure out is...

Lets say PPM of tap water is 200, vs RO water which could be 50...

if wanted my PPM to be 400 for my reservoir, and Im using tap water with a base of 200 already, Then I would only be able to put as much nutrients in to make it 400, right? But if i was using water if a base of 50 PPM, then I would have 150 extra PPM of nutrients?

So does it slow down growth by using water with a high base PPM since you can't add as much nutrients? or does it really not matter...

I'm just beginning with hydro myself, and you are asking the same questions I was asking an expert, yesterday ... yes, you are correct on calculating the ppm limit ... whatever is left after your water ppm, is the amount of nutrients you would be able to add... and, if you cant add much nutrient, growth will slow ... plus, the high ppm could be because of bad contaminants ... RO water is very low, mine is 004 ... but, with RO, you also have to add Cal-Mag Plus, and I assume that will add to the ppm, as well ... but, remember I'm very new at this, I haven't even set up my equipment yet, still researching ... :smokin:

Illusion
10-20-2007, 08:22 PM
Thank you so much for the reply, its the confirmation I needed and makes sense to me

Do you know of a place to purchase RO water in bulk without purchasing a RO system? I can't really afford one

the image reaper
10-20-2007, 09:11 PM
most grocery stores have a machine, where you either refill your own jugs, or buy the empties there ... it used to be 25-cents/gal, but I haven't paid any attention lately ... be sure to check the pH, it is likely acidic ... :smokin:

macro
11-01-2007, 12:21 AM
I've been adding nutes on TOP of my tap water, if I had a tap water with a TDS of 200 and wanted nutes at 400 I would add 400PPM worth of nutes into the res.

If I used RO water with a TDS of 50 I would add 400ppm of nutes

Maybe I've been doing it wrong but thats how i've been doing it and it seems to work great,

but im only on my first grow so dint listen to me too seriously

Illusion
11-01-2007, 02:45 AM
so always add 400 ppm in that situation?

herbie the love bud
11-01-2007, 04:05 AM
no don't do that. Image R seems to be right from what I've heard everywhere. I'm struggling with the same issue.

MVP
11-01-2007, 04:28 AM
The TOTAL PPM should be what you target. Add your nutes to the res water, then take a PPM measurement of the well mixed solution in your res. In other words your target is your nutes + water = 400 PPM... make sense?

the image reaper
11-01-2007, 04:14 PM
yeah, it is the TOTAL PPM you are looking for, you want to stay in your 'range', and the tapwater ppm must be included in the math :smokin:

Illusion
11-01-2007, 07:30 PM
Exellent. Thank you!

:thumbsup:

PharmaCan
11-01-2007, 11:24 PM
I'm just beginning with hydro myself, and you are asking the same questions I was asking an expert, yesterday ... yes, you are correct on calculating the ppm limit ... whatever is left after your water ppm, is the amount of nutrients you would be able to add... and, if you cant add much nutrient, growth will slow ... plus, the high ppm could be because of bad contaminants ... RO water is very low, mine is 004 ... but, with RO, you also have to add Cal-Mag Plus, and I assume that will add to the ppm, as well ... but, remember I'm very new at this, I haven't even set up my equipment yet, still researching ... :smokin:

Hmmm... I'm operating under the premise that it is just the opposite - that you factor the water's ppm out of the equation. The nutrient levels are predicated upon the what is best for the plant during its various stages of life; maximum/ideal nutes for maximum/ideal growth. The stuff in your water is not nutrients - it could be anything. So why count it towards the nutrient value that you want to make available to the plants?

Just to be clear, if my tap water is 200 and my target ppm of nutes is 1,000 - my target ppm for the solution would be 1,200ppm.

It should also be noted that supplements DO NOT count towards your nute ppm. So, if, for example, you want to add calmag+, you would do so AFTER establishing the correct nutrient solution ppm with ONLY your nutrients (G-B-M if using 3-part). It is totally irrelevant what the ppm is after adding the supplements.

I switched from R/O to tap water recently and I'm still adding Calmag+ to my solution. I don't know if I need it or not, but I'm only using 1ml/gal so it's just kinda cheap insurance as far as I'm concerned.

PC :smokin:

xcrispi
11-01-2007, 11:39 PM
P.C- QUOTE = I switched from R/O to tap water recently and I'm still adding Calmag+ to my solution. I don't know if I need it or not, but I'm only using 1ml/gal so it's just kinda cheap insurance as far as I'm concerned.

Hell yes P.C - It's much easier to avoid a def. all together - verses trying to diag. / fix 1 . :thumbsup:

I didn't add in the base ppm of my tapwater either before I got my r/o system . But I do disagree about the additives coment . What if the additive is Koolbloom = a blast of phos. It ups my ppm by 200 or better . Do you use any boosters etc... ?

Peace
Crispi :stoned:

MVP
11-01-2007, 11:56 PM
If you add Botanicare Sweet it will jack up your PPM as well. Way the F* up there!

PharmaCan
11-02-2007, 12:00 AM
P.C- QUOTE = But I do disagree about the additives coment . What if the additive is Koolbloom = a blast of phos. It ups my ppm by 200 or better . Do you use any boosters etc... ?

Peace
Crispi :stoned:

I use AN 3-part plus CalMag+, Sweet, Molasses and Liquid Karma.

PC :smokin:

socialistpete
11-02-2007, 02:22 AM
Wow this is a great thread! I think a lot of people including myself have these questions. Keep the replies coming.:thumbsup:

the image reaper
11-02-2007, 08:35 PM
I'm hoping for the definitive answer as to whether the base-water ppm are included in the Total or not ... my base ppm is small enough it wouldn't matter, but I am curious ... I'm new at this, but that's how I've been reading it ... :smokin:

MVP
11-03-2007, 11:24 PM
It is total PPM that you target. I just spoke to the guys at Green Coast Hydro (very knowledgable store in Socal) and they confirmed it for me. This is one of the main reasons for using RO water -- so that you can add more nutes to achieve the total PPM. Right now my tap water is just under 300 PPM alone, so going to RO water will allow me to add 33% more nutes since my target PPM is 1200. (currently water = 300 PPM) + (nutes = 900 PPM) = (Total PPM of 1200)... Got it?

Also, add micronutients, then additives (root conditioner, sweet, etc), then your grow/bloom in that order keeping tabs on PPM as you add ingredients.

Happy hydro growing folks!

MVP :jointsmile:

rhizome
11-04-2007, 12:56 AM
MVP's correct- without a very good analysis of your source water, you want to want to build that into your desired EC/ppm.

This is because conductivity is a very gross measurement- it tells you that something is in there, but not what. This can be likened to weighing a box to find out what's in it- you can establish that there are twenty pounds in there, but you don't know if it's books or rocks- only that it's heavy.

You don't know that the EC of your source water is due to inert contaminants that you can ignore, or contaminants that will sum with the nutrients that you are adding ( also, technically, contaminants from the meter's point of view) to cause an overdose condition. Therefore, you must be conservative and build that number into your total.

When you're in a situation where you have really good, up-to-date analysis of your source water- differant story. F'rinstance, if I saw that my source water showed an EC of .2 ( which would be a ppm reading of 140)-

-and analysis showed it to be mostly calcium:
I'd cut out the Cal-Mag and bump in some Sweet ( high Mg) w/ Pure Blend, or drop the micro in GH Flora by a bit, using some epson salts and an iron chelate on the side, or whatever else depending on what nute system I was using to account for the extra Ca and keep everything else in ratio.

-and analysis showed it to be primarily silica
Well, h#ll then, full speed ahead! but I'd know why pH maintenance was a little twitchy.

- and analysis showed it to be ferrous compounds

Well, I'd feel fairly safe using a three-part, dropping micro fractionally and supping w/ Cal-mag. If it was way bad I'd think About A/B ing it through a filter ( acidify- only need a bit before you add nutes, run through filter to catch precipitates, basify, run through filter to catch precipitates, re-acidify to return to useable pH- you can shake a lot of sh!t out this way, w/o using a lot of chemistry if you think it through.)

Anyway, etc- ya see where I'm going.


In newer muni water systems, you can get a fairly accurate report from the supplier. Older stuff- run ya about $15 thru yer local ag extension.

These #'s can change a LOT according to changes in processing agents, local watertable, weather and usage patterns-
Farmers will generally have supplies tested at least every 14 days.

Opie Yutts
11-04-2007, 07:13 AM
Everything that is in your solution counts toward your target PPM. That's why it's your target. A target isn't something that you try to achieve, but it's OK if you go over by 30%. No, you actually want to try and achieve your target. That includes additives, nutrients, whatever comes out of your tap, fly poop, etc. Your tap water may contain desirable nutrients, especially if it's well water. Copper, iron, zinc, all sorts of crap that the plant can use, and some of which it actually needs. You've gotta count this stuff.

PharmaCan
11-04-2007, 04:26 PM
Rhizome - I was hoping you'd come along and clear this up. We can always count on you for definitive answers. :thumbsup:

I was hauling RO water until a couple weeks ago. But I have some bad back problems and lifting those bottles was getting to be problematic, so I switched to tap water. I guess I'll switch back to RO - I want to know exactly what my plants are getting.

...guess I'm going to have to buy an RO unit.

PC :smokin: