Water Quality

[VapedOutJoe]

What is the range for water quality needed for best grow results? Hydro vs Soil

PH
Alkalinity
Calcium
Magnesium
Potasium
Sodium
Total Harness
etc

I've been searching, but there is so much info on individual water issues, I can't find a chart for this. Anyone have one, or know the best averages?

“Up is down… well that’s just maddeningly unhelpful. Why are these things never clear?”
“Clear as mud, Jackie”.
- Captain Jack Sparrow

Thanks

 

[Hogdady]

Ideally it would be neutral ph with no solids (0 ppm)

 

[VapedOutJoe]

I see. Then you would add in all of the solids needed..

 

[GonzoBot]

Ideally it would be neutral ph with no solids (0 ppm)

On soil it would be suicide ^^

 

[VapedOutJoe]

On soil it would be suicide ^^

Suicide? Murder? Neglect? Abuse? Not on my watch.

Any charts out there?

For instance - would a total alkalinity of 200ppm be too high? Is 20 ppm too low?

 

[Hogdady]

On soil it would be suicide ^^

Please explain.....

 

[Hogdady]

Suicide? Murder? Neglect? Abuse? Not on my watch.

Any charts out there?

For instance - would a total alkalinity of 200ppm be too high? Is 20 ppm too low?

Below 7.0 ph......acid
Above 7.0 ph.....alkaline

You would add acid or alkaline to achieve correct ph...what you were lookin' for?

 

[Hogdady]

I see. Then you would add in all of the solids needed..

Yes...to the levels that you prefer...

 

[VapedOutJoe]

Thanks Hogdady! Can't rep you again, but thank you.
I 've read a lot about people's tap water levels but havn't figured out the correct levels. I just go with what seems to make the plants happiest, and use plant abuse charts to see what issues plants may be having. I know my tap water isn't the best, but was kinda wondering what the 'best' looked like.

 

[Hogdady]

Thanks Hogdady! Can't rep you again, but thank you.
I 've read a lot about people's tap water levels but havn't figured out the correct levels. I just go with what seems to make the plants happiest, and use plant abuse charts to see what issues plants may be having. I know my tap water isn't the best, but was kinda wondering what the 'best' looked like.

Many folks use R/O water which will remove almost all solids. Then they add the solids (nutrients) and then adjust for the ph they desire.

When you are measuring ppm's to know your nutrient strength, the ppm's of your water will be part of this number. Example...your water has 500 ppm's of TDS (total dissolved solids). You want to feed your plants with 1500 ppm's nute/water mix. You only have room for 1000 ppm's of nutrients to achieve the 1500 ppm total. If the water has close to 0 ppm's of TDS, you can add 1500 ppm's of nutrients to achieve your 1500 ppm target.

 

[VapedOutJoe]

I see. That actually makes more sense to me then a chart on water needs. But it does bring up a question of:

If I am using tap water, what are the max numbers I should have per solid?
So if my water from tap has 18 ppm of calcium, is that high? Should I save and invest in a R/O system? Same for other solids that matter.

 

[Hogdady]

I'm not aware of any individual element guidelines. I think the best you can do is to check your tap water for TDS and if the numbers are very high, you may want to consider an alternative. Bear in mind that the tap water will change in TDS and ph frequently.

 

[GonzoBot]

Please explain.....

Working in a laboratory specialized in Soil, Water and Air analysis I can tell you that the fewer salts (EC=0, no salts at all) water has, the more salts are soluble in said water. If you would water a pot of soil constantly with "Demin" (laboratory term for water with ec 0) the soil would loose alot of its nutes very quickly.

So my thought is: Water a plant on soil with demin and you would gradually drain the nutes out of the soil. Of course you can compensate this by adding nutes to the demin water but then youd have a.) to pay for an environmentally harmfull product (demin water is often still destilled; b.) pay for nutes just to stop the water drain the very same nutes you added out of the soil.

Little hint: Try to drink demin water for 1 week. If you are still alive then I donate you 10 420points ^^ (Dont try this at home, demin water is actually "poison", just like salt water)

So again:
Watering soil with demin=draining nutes out of soil fast
Watering soil with demin+nutes=silly and expensive

On Hydro its something else. There using demin with nutes actually gives you more control over what the plants will "eat". If you take tap water for hydro you have to compensate the natural EC of the tap water. If you are unlucky and have a natural EC of 0,8-1,0 in your tap water and use the standard feeding scheme you will oversalt your medium quite fast. But thats another story.

 

[Hogdady]

Working in a laboratory specialized in Soil, Water and Air analysis I can tell you that the fewer salts (EC=0, no salts at all) water has, the more salts are soluble in said water. If you would water a pot of soil constantly with "Demin" (laboratory term for water with ec 0) the soil would loose alot of its nutes very quickly.

Precisely the reason we flush plants in soil...

So again:
Watering soil with demin=draining nutes out of soil fast
Watering soil with demin+nutes=silly and expensive

The problem as I see it is that you have no clue what solids are in your tap water. Using "demin" and adding the nutrients of your choosing gives you control of what is going into the soil. Am I wrong here?

 

[GonzoBot]

Hi again!

1.) Iam a very big oponent of "flushing" soil. Best idea is just to lay off any nutes in the last ten days. Flushing in the sense of watering until you have massive ammounts of drainage is a deluxe "mold stimulator". Just to keep the terms "flushing" and "starving out" divided.

Here is a good (Hippe proof ^^) source of information (Mandala Seeds):





"Can I flush on soil?

You should avoid watering more than normal and having a lot of run-off in soil grows. Heavy watering or flushing/rinsing the soil can cause bud mold (run-off also washes out nutrients). Instead, give the plants their daily requirements and water at the start of the light cycle. Even if they let the leaves hang a bit now and then in the final 10+ days it's better than over-watering at this stage.

In principle you should never have to flush in soil cultivation. It leads to all sorts of complications like waterlogged soil, nutrient run-off, fungus, etc.

If you already know you have made a mistake like over-watering, always wait for plant health to improve before taking steps further with feeding, etc. You can't "cure" anything with feeding unless there is a real nutrient deficiency at hand. You won't get a nutrient deficiency in soil if plants are in quality soil, have an adequate container size, and the pH of your water is OK. If the pH of your water is not within range you need to correct it... feeding would only stress the plants even more because they can't take up the nutrients in a substrate watered with a wrong pH.

Flushing your soil prior to harvest does NOT improve aroma and taste of the buds. It DOES increase chances of getting bud mold within 48 hours and can easily lead to other fungal infections which threaten your crop. The smart way to increase aroma is to buy quality soil and mix it with beneficial aroma enhancers such as worm manure and compost. Rinsing substrates should only be applied to hydroponic cultivations. The idea is to water with a very low EC, special ripening products, or only pure water a few days or a week prior to harvest - again, there should be no need to flush large amounts of water through the system. In coco coir this can also lead to a soggy substrate and increase the risk of bud mold."










2.) Well as I said: Using demin and nutes will give you alot more control over the nutes you exactly give the plant. But there are several points to take into consideration:

-As I said, demin water CAN be a very evironmental bad product. Please try and find out if it was "destilled" (very bad) or "demineralised" (good). The product is the same, the impact on CO2 production is huge. Dont forget that.

-Giving demin+nutes if growing on soil somewhat takes growing on soil ad absurdum. The tap water has indeed some "ballast nutes" like calc or chlorine (all those things increase EC) and other stuff. Still alot of the nutes in tap water are absolutely ok, like magnesium and other trace minerals. Still, good soil has enough nutes to keep your plants A1 healthy and well-fed for at least 6 weeks.

-Giving demin+nutes on soil brings you another problem! You have to count in the EC of the soil or better said, the EC the soil will share with the water given. So using demin and nutes (on soil) will only make sense if you can account and compensate for the extra EC the water will get via the soil. Overfeeding is in my opinion very more likely to happen.

-Soil has various buffers. If you use tap water and soil you dont have to compensate the tap waters EC (if your tap water hasnt a very very high EC level "au natural"). An example: Fresh and good soil will capture exessive ammounts of H+ or OH- and buffer heavy metall ions.

I think using demin+nutes on soil from beginning to end is like taking boats into the dessert. Id rather spend my money on a high class laboratory pH/EC-Meter and let the soil do what it can do best: provide the food and an environment the plant is used to since milleniums of years.

My 0.02$ from a scientists point view.


PS: There is a reason why we divide between hydro and soil. ^^

 

[SoCaler]

My water swings from 400 to 500 ppm, and have no idea whats in it .
That's the reason I got an R.O. system, now I know whats in it and my pH is
much more stable.

 

[VapedOutJoe]

SoCaler, Do you have any input on a good RO system? Is it better to get an inline one that is portable, or one that fits on the kitchen sink so you can drink it too? etc. Thanks,

 

[Hogdady]

SoCaler, Do you have any input on a good RO system? Is it better to get an inline one that is portable, or one that fits on the kitchen sink so you can drink it too? etc. Thanks,

R/O systems are rated by gallons per day (24 hour period). Small scale drinking water systems would be way too small. I was looking at the GE Merlin system (720 gpd) at one time. They also generate lots of waste water...

 

[VapedOutJoe]

Thanks Hog. I am looking into some 100 gpd ones that are inline and can be put away when not in use. Hook that up to fill a large res for a half day and I can have water for a week or 2. I think I would use half tap and half RO to save some time, and waste water. I've done that with water I've purchased at the store, distilled or RO water and mixed half tap water. Amazing how much less PH down is needed when doing this, even though the waters mixed together still have the same PH as the tap straight. TDS is lowered, so that's my guess as to why it lowers easier.

 

[Hogdady]