padyakol
- 58
- 18
anyone out here has done adding ion exchange resin to your hydroponic system? anyone care to shed some info on this pls. do so. big help!
sedate
- 948
- 63
Wow. Neat stuff.
Um. So I seriously have no idea what the answer to your question is - yet - but this stuff looks pretty cool:
http://en.wikipedia.org/wiki/Ion-exchange_resin
Um. So I seriously have no idea what the answer to your question is - yet - but this stuff looks pretty cool:
http://en.wikipedia.org/wiki/Ion-exchange_resin
Seamaiden
Living dead girl
- 23,596
- 638
I have only ever used ion exchange resins to lock onto very specific compounds, e.g. phosphorous/phosphates in a saltwater aquarium, or final water 'polishing/softening' in a South American tetriid tank. This is why I never answered this question, because I know nothing about it.
That also suggests to me that growers are not using ion exchange resins in their reservoirs. The DI portion of RO/DI is deionization, which is a resin. (reverse osmosis with deionization)
That also suggests to me that growers are not using ion exchange resins in their reservoirs. The DI portion of RO/DI is deionization, which is a resin. (reverse osmosis with deionization)
J
Jalisco Kid
Guest
I did a thread on it here I believe about two years back.JK
Seamaiden
Living dead girl
- 23,596
- 638
Uh oh, could it have been lost during the switch-over?
woodsmaneh
- 1,724
- 263
I use a DI filter on my RO system which helps take my ppm's down further, I don't think you really need one I just was not sure when I purchased the system. You use beads that are chemically treated to attract minerals. Mine are green to start and finish looking brown when used up, I still use it as I have enough replacement resin to last 20 years, no fooling, I bought 10 pounds of the stuff.
Deionized Water has the ions removed. Tap water is usually full of ions from the soil (Na+, Ca2+), from the pipes (Fe2+, Cu2+), and other sources. Water is usually deionized by using an ion exchange process.
Water with ions in it is also quite a lot more electrically conductive than water without ions in it, so when measuring PPM I like to start as close to zero as I can than add back to it what I want in it.
Below is a pix of my setup, far right is the booster pump that runs at 85psi, than the dirt filter, than the carbon filter than up top to the white canister that has the RO membrane than out to the first DI than on to a second DI. I don't use 2 DI's anymore just one. It's great for washing your car.
Pix won't load be back
Deionized Water has the ions removed. Tap water is usually full of ions from the soil (Na+, Ca2+), from the pipes (Fe2+, Cu2+), and other sources. Water is usually deionized by using an ion exchange process.
Water with ions in it is also quite a lot more electrically conductive than water without ions in it, so when measuring PPM I like to start as close to zero as I can than add back to it what I want in it.
Below is a pix of my setup, far right is the booster pump that runs at 85psi, than the dirt filter, than the carbon filter than up top to the white canister that has the RO membrane than out to the first DI than on to a second DI. I don't use 2 DI's anymore just one. It's great for washing your car.
Pix won't load be back
padyakol
- 58
- 18
very infornative seamaiden! hope to see some pictures of your setup
padyakol
- 58
- 18
Hope to see pics of your setup!:)
stutter
- 325
- 93
this might help
Acid
Phosphoric acid is probably the most common used to control pH. However, it does present some difficulty as shown up in your case. Because the phosphorus (P) component of a typical tomato feed is relatively modest at around 40 ppm, adding a significant amount of phosphoric acid will give a substantial rise in the P content of the feed.
The main alternative is nitric acid, which has the advantage that the normal feed level is much higher at about 200 ppm N, hence adding nitric acid will have a much less relative impact on the N content of the feed. Unfortunately, concentrated nitric acid is a nasty liquid to handle, especially as it gives off irritating brown fumes, hence why phosphoric acid is more popular.
pH drift
In order to reduce the amount of phosphoric acid needed, you need to reduce the pH rise so you do not need to keep lowering your feed pH. This is done by increasing the ammonium content of your feed. Ammonium nitrate solid is banned for sale except if you have a special security licence. It is available in liquid form, but this is at half strength and is relatively expensive.
There is an alternative. This is to add mono ammonium phosphate (MAP) to your mix to give the added amount of ammonium that you need. You are no doubt adding phosphorus in the form of mono potassium phosphate (MKP). In order to keep your phosphate level steady, as you add MAP you reduce the amount of MKP accordingly. Without more detail, I can’t give a definite recommendation for the relative proportions, however about half each MAP and MKP would be in the ballpark, to eliminate your upward pH drift.
Ammonium addition mechanism
How does increasing the ammonium content of the feed reduce upward pH drift?
Two forms of nitrogen (N) are used in hydroponic solutions – nitrate ions (NO3-) negatively charged ions (known as anions) and ammonium ions (NH4+) positively charged ions (known as cations). In soil growing, any ammonium ions present are locked onto the soil particles and converted (the process of ‘nitrification’) to nitrate ions before being taken up by the plants. Thus, in soil, the plant is basically not exposed to free ammonium ions. Contrasting with soil growing, in hydroponic solutions ammonium ions remain available and are taken up very quickly, much faster than nitrate ions.
Especially during the vegetative stage, plants are taking up high proportions of NO3- ions. In order to remain in electrical balance they will be exuding negatively charged ions, which raise the pH. If NH4+ ions are introduced into the solution, they are rapidly taken up by the plants. Therefore, the plants compensate by exuding positively charged ions to maintain the electrical balance. These are hydrogen ions, H+, the ‘acid’ ion. Consequently, the pH of the root zone solution will fall.
Therefore, increasing the proportion of ammonium in the feed will result in a relative lowering of the pH of the root zone solution. Reducing the proportion of ammonium in the feed will result in a relative raising of the pH of the root zone solution. This applies to all systems whether recirculating or not. For example, the pH of a recirculating solution may be over 7 even though the feed solution pH has been pulled down to below 6. This is a situation where the use of phosphoric acid to lower the pH will lead to a severe imbalance of high P levels developing in the recirculating solution. Increasing the proportion of ammonium ions in the feed should allow feeding at about pH 6 and to maintain that level with time.
When doing calculations, remember to include the ammonium that comes as part of the calcium nitrate. Typically, about 8% on the nitrogen in calcium nitrate is in the ammonium form, and about 92% in the nitrate form.
Acid
Phosphoric acid is probably the most common used to control pH. However, it does present some difficulty as shown up in your case. Because the phosphorus (P) component of a typical tomato feed is relatively modest at around 40 ppm, adding a significant amount of phosphoric acid will give a substantial rise in the P content of the feed.
The main alternative is nitric acid, which has the advantage that the normal feed level is much higher at about 200 ppm N, hence adding nitric acid will have a much less relative impact on the N content of the feed. Unfortunately, concentrated nitric acid is a nasty liquid to handle, especially as it gives off irritating brown fumes, hence why phosphoric acid is more popular.
pH drift
In order to reduce the amount of phosphoric acid needed, you need to reduce the pH rise so you do not need to keep lowering your feed pH. This is done by increasing the ammonium content of your feed. Ammonium nitrate solid is banned for sale except if you have a special security licence. It is available in liquid form, but this is at half strength and is relatively expensive.
There is an alternative. This is to add mono ammonium phosphate (MAP) to your mix to give the added amount of ammonium that you need. You are no doubt adding phosphorus in the form of mono potassium phosphate (MKP). In order to keep your phosphate level steady, as you add MAP you reduce the amount of MKP accordingly. Without more detail, I can’t give a definite recommendation for the relative proportions, however about half each MAP and MKP would be in the ballpark, to eliminate your upward pH drift.
Ammonium addition mechanism
How does increasing the ammonium content of the feed reduce upward pH drift?
Two forms of nitrogen (N) are used in hydroponic solutions – nitrate ions (NO3-) negatively charged ions (known as anions) and ammonium ions (NH4+) positively charged ions (known as cations). In soil growing, any ammonium ions present are locked onto the soil particles and converted (the process of ‘nitrification’) to nitrate ions before being taken up by the plants. Thus, in soil, the plant is basically not exposed to free ammonium ions. Contrasting with soil growing, in hydroponic solutions ammonium ions remain available and are taken up very quickly, much faster than nitrate ions.
Especially during the vegetative stage, plants are taking up high proportions of NO3- ions. In order to remain in electrical balance they will be exuding negatively charged ions, which raise the pH. If NH4+ ions are introduced into the solution, they are rapidly taken up by the plants. Therefore, the plants compensate by exuding positively charged ions to maintain the electrical balance. These are hydrogen ions, H+, the ‘acid’ ion. Consequently, the pH of the root zone solution will fall.
Therefore, increasing the proportion of ammonium in the feed will result in a relative lowering of the pH of the root zone solution. Reducing the proportion of ammonium in the feed will result in a relative raising of the pH of the root zone solution. This applies to all systems whether recirculating or not. For example, the pH of a recirculating solution may be over 7 even though the feed solution pH has been pulled down to below 6. This is a situation where the use of phosphoric acid to lower the pH will lead to a severe imbalance of high P levels developing in the recirculating solution. Increasing the proportion of ammonium ions in the feed should allow feeding at about pH 6 and to maintain that level with time.
When doing calculations, remember to include the ammonium that comes as part of the calcium nitrate. Typically, about 8% on the nitrogen in calcium nitrate is in the ammonium form, and about 92% in the nitrate form.
woodsmaneh
- 1,724
- 263
here are the pix of my system the DI canisters are the two on the left. The second from the left you can see the color at the bottom is brown because the beads coating is doing it's job. The far left has fresh beads in it.
Latest posts
-
Outdoor grow in Southeast Michigan 2024- cpurola posted
-
To top or not to top?- HerbalEdu posted
-
Is my plant a Hermie?- BudRanger1919 posted
-
BSuspicious ballz - are these normal?
- Budclarkson posted
