How to mix nutes for hydro

[Aqua Man]

I was describing what I noticed just with tap water and ro water in separate buckets, no plants, no nutes, no ph adjustments, no other variables. I tested this because I found when I was using the ro water (specifically early in veg) the ph would slightly drop over time from where I had adjusted it and with tap water it either stayed the same or slightly rose. After some research just now I think I found some relevant info:

"Because reverse osmosis removes the minerals in water the water will then react with carbon dioxide upon exposure to air to form carbolic acids, thus lowering the pH. The resultant pH will depend on the initial water chemistry. It cannot be predicted. "

and more technical

"When water is passed through a semi permeable membrane using pressure, many organic and inorganic compounds fail to pass through, however gases like Carbon Dioxide make it to the other side. CO2 combines with the free OH- ions in water to form acidic HCO3, while the H+ ions fail to find any substance to interact with as most of the impurities have been removed through the RO process.

CO2 + H2O <--> H+ + HCO3-

As a result, water has a positive balance of H+ ion, lowering its pH and making it acidic. (Again, remember, pH is measure of H+ with a minus. No more chemistry further, we promise!). The greater the amount of CO2 in your water, the greater is the drop in pH level"

I could possibly attribute. The ph difference between tap and RO with only nutrients to evaporation. Ph will drop ass ppm increases this effect will be less pronounced in tap because it's more alkaline.

In terms of CO2 the water will strive to reach equalibrium with proper aeration it does. Concentration will not be higher. If you increase the CO2 concentrations of the atmosphere the water will try to rebalance itself by absorbing more CO2 this can lower ph by forming more carbonic acid. Again this effect can be more or less pronounced depending on the alkalinity of the water. Which in turn the ph may change a little or alot. It's the alkalinity thats in control.

of course there are ways to force more CO2 into water but they require increased pressure and Derek time CO2 unlike oxygen is much easier to dissolve in water and likewise much easier to offgas from water. I used to to this with a CO2 reactor I built to control ph

I think we are saying the same thing

 

[Dankness420]

Easy to test and find out. While it can contribute I cant see it being responsible for a spike that big. I would say your ph is not stable but it could be contributing if that's the case. Are you finding this ph rise in both?

And if it is contributing I would stop using it.

Both are rising bust one keeps hitting the 7 mark and one the 6.8, I tried the Baking soda method yesterday, changed the res added baking soda, nutes, and ph down, one was ph'd to 5.8 the other to 6.1, today the 5.8 one was 6.5 ph, the 6.1 was around 7.2, I dont really know I'll take a picture of the rocks I'm using, I added some more baking soda and ph down and phd both to 5.8, gonna wait till tonight and re measure, the plants did grow tbh but I'm not liking the colours one bit, greenish yellow, they look healthy but the color is my issue, if it's the rocks, would it be possible to dig the sponge out and change out the rocks or would that no be good for the plant? Might as well do it now than later:/

 

[Dankness420]

This is the clay I'm using. And this is what it says on the website:
CHARACTERISTICS
Neutral pH and chemically inert: Laterlite Agri is specifically formulated to be chemically inert with a neutral pH, and is therefore highly compatible with all types of plants and crops.

I will try to get my hands on potassium bicarbonate if that would make a difference rather than baking soda

 

[Dankness420]

So I have checked my ph again just now and it shot from 5.8 to 6.5:/ any ideas guys I'm starting to get frustrated

 

[Aqua Man]

So I have checked my ph again just now and it shot from 5.8 to 6.5:/ any ideas guys I'm starting to get frustrated

Ok are you using tap water? Are you aerating it first?

I gave you small amounts to start with. Use tsp of baking soda. Then nutrients then ph down in that order ph last always or your ph will not be right.

 

[Aqua Man]

So I have checked my ph again just now and it shot from 5.8 to 6.5:/ any ideas guys I'm starting to get frustrated

Can you take a picture of your ph down for me? label and ingredients.

 

[Dankness420]

Ok are you using tap water? Are you aerating it first?

I gave you small amounts to start with. Use tsp of baking soda. Then nutrients then ph down in that order ph last always or your ph will not be right.

I have used that exact method and order but no luck, I have increased the baking soda amount to see what would happen.

 

[Dankness420]

I am

I have used that exact method and order but no luck, I have increased the baking soda amount to see what would happen.

Using tap water and no I am not aereating it first, I let it sit out for a bit and I dont use an air stone since the system is supposed to aerate the water

 

[Aqua Man]

I am

Using tap water and no I am not aereating it first, I let it sit out for a bit and I dont use an air stone since the system is supposed to aerate the water

Ok that could be part of the problem. So you may need to go back and re ph the water a few hrs after. Tap water is a closed system so carbonic acid in the system take a while to off gas CO2 and the ph will rise. You can either adjust ph after a couple hrs or aerate the water for a few hours before adding.

Increasing the baking soda to 1tsp per 5 gal should solve it.

GH ph down is good not as good as straight food grade phosphoric acid. The nitric acid that partially makes up GH ph down is a bit weaker. But it does also contain phosphoric acid.

 

[Dankness420]

I hope that helps, do you thing I should add an air stone to the reservoir if I can get the air tube through?

 

[Aqua Man]

I hope that helps, do you thing I should add an air stone to the reservoir if I can get the air tube through?

Always a good idea to aerate water. It help the gas exchange so that balances the CO2 levels and all gasses for that matter between the air and water.

 

[Dankness420]

Always a good idea to aerate water. It help the gas exchange so that balances the CO2 levels and all gasses for that matter between the air and water.

Sounds good I'll get to it and let you know how it goes

 

[FourthCity]

Sounds good I'll get to it and let you know how it goes

A little off topic but since we are discussing improving the aquafarm by adding an airstone (I highly agree with doing this!) I would also recommend before you start you next grow drilling some larger holes in the bottom of the top part of the unit. You will know what I mean once this grow is done and you see how jam packed with roots those holes become.

 

[Dankness420]

A little off topic but since we are discussing improving the aquafarm by adding an airstone (I highly agree with doing this!) I would also recommend before you start you next grow drilling some larger holes in the bottom of the top part of the unit. You will know what I mean once this grow is done and you see how jam packed with roots those holes become.

I actually thought about this seeing how small they are but didnt want to mess with the setup, I'll definitely do that once this is all done successfully I hope.

 

[Aqua Man]

So all fixed now?