Irrigation water ph.

[FountainMan]

I have a custom irrigation system that uses pond water to irrigate. Water is held in a 27-gallon tank (tough-tote) for irrigation purposes. At this point, I'm treating this like a hydroponic system although it's not.

Anyways, the system employs nitrifying bacteria to break down organic matter and waste and turn it into nitrates as a natural fertilizer. Did some research, I'm reading that this process works best at a PH of 7.5-8. The PH of my tank is a bit high in the mid 8s. Is this okay or should it be lowered?

 

[DirtMechanic]

I have a custom irrigation system that uses pond water to irrigate. Water is held in a 27-gallon tank (tough-tote) for irrigation purposes. At this point, I'm treating this like a hydroponic system although it's not.

Anyways, the system employs nitrifying bacteria to break down organic matter and waste and turn it into nitrates as a natural fertilizer. Did some research, I'm reading that this process works best at a PH of 7.5-8. The PH of my tank is a bit high in the mid 8s. Is this okay or should it be lowered?

Do you have an air bubbler in it? Fundamentally you are brewing high bacteria compost tea is why I ask. Also, that oxidation the bacteria are giving you is going to range down as the components are composted, resulting in a lower, balance pH much like a compost pile would show you. That completion depends on how long it sets of course. I can compost lemons and they have a low pH but once composted it is neutralized. What is it in your tank that is high? The equipment you used to measure pH is what? Why are you not just adding sugar to increase the C content while attracting bacteria? The fertilizer content is by mass and I wonder at the cost of N for such a small amount that is in water. If water is 8.3 lbs per gallon how many gallons will it take to give 1 lb of N?

 

[FountainMan]

Do you have an air bubbler in it? Fundamentally you are brewing high bacteria compost tea is why I ask. Also, that oxidation the bacteria are giving you is going to range down as the components are composted, resulting in a lower, balance pH much like a compost pile would show you. That completion depends on how long it sets of course. I can compost lemons and they have a low pH but once composted it is neutralized. What is it in your tank that is high? The equipment you used to measure pH is what? Why are you not just adding sugar to increase the C content while attracting bacteria?

The water is aerated via Marine Metal Fish Saver (Cone Spray aerator). The water is monitored via this, https://a.co/d/91UyADX. Might buy a PH testing kit just to rule out inaccuracies. I’ll try the sugar and see if that helps.

Further reading last night showed that a PH between 7.5-9.5 is ideal for the process so my concerns have been laid to rest. But I’ll definitely try the lemon and sugar trick.

Thanks.

 

[DirtMechanic]

The water is aerated via Marine Metal Fish Saver (Cone Spray aerator). The water is monitored via this, https://a.co/d/91UyADX. Might buy a PH testing kit just to rule out inaccuracies. I’ll try the sugar and see if that helps.

Further reading last night showed that a PH between 7.5-9.5 is ideal for the process so my concerns have been laid to rest. But I’ll definitely try the lemon and sugar trick.

Thanks.

Please, do not acidify your tea. Lemons were a process example the exact opposite of your question for illumination purposes only. Citric acid is a preservative that will kill your bacteria. Carbon, Oxygen and Hydrogen are the primary nutrients, just to clarify why sugar is useful.

Holy cow that looks like a grower setup. Are you sure you should not just kill everything in the water, filter it through charcoals and then use it inside that building? If you pipe inside the outside water it will get funky fungi.

 

[FountainMan]

Please, do not acidify your tea. Lemons were a process example the exact opposite of your question for illumination purposes only. Citric acid is a preservative that will kill your bacteria. Carbon, Oxygen and Hydrogen are the primary nutrients, just to clarify why sugar is useful.

Holy cow that looks like a grower setup. Are you sure you should not just kill everything in the water, filter it through charcoals and then use it inside that building? If you pipe inside the outside water it will get funky fungi.

View attachment 91351

I apologize, the vernacular is throwing me off. Could you rephrase?

 

[DirtMechanic]

I apologize, the vernacular is throwing me off. Could you rephrase?

Sure, the context is how you are using the water. So you said its not hydroponics but I suspect you are setting up a ebb and flow system? That will be really different than outdoor irrigation. Where does your water end up? Back in the tank?

 

[FountainMan]

Sure, the context is how you are using the water. So you said its not hydroponics but I suspect you are setting up a ebb and flow system? That will be really different than outdoor irrigation. Where does your water end up? Back in the tank?

A little tour of the system to explain how everything works. This is for an apartment patio BTW.

These two pipes are the backflush from a pressurized bio filter (the straight piece in front) and pond overflow drain (the pipe behind that's coming in at an angle). This is where the tank gets its water.

The holding tank holds 27 gallons of water until it's needed for irrigation purposes. While the water is stored in here, the aerator provides oxygen to the nitrifying bacteria in this system. The pump for the aerator sits in a box of bio-balls which house colonies of nitrifying bacteria. The PH, temperature, and TDS probes aren't shown, but are submerged about 6" deep behind the white elbow on the left.

This is the solenoid valve (Melnor Hydrologic 4 zone hose timer) and micro-irrigation manifolds. This is attached to a 4500 gph pump that pushes the water through this. Not shown, but there's a fine mesh screen Y filter behind this to keep silt and other particulate matter out of the lines. That's equipped with an automatic flush-out valve. Also not shown is the controller that opens and closes the solenoid valves. All those little tubes carry the water to various parts of the garden. Each of the 4 valves has a different schedule and watering duration and each line is connected to the appropriate valve based on the watering needs of what that line is watering.

A few pictures of some of the sprayer/sprinkler heads that deliver the water to various planters. This is where the water ends up. The idea is to take advantage of the nitrification process to act as a natural fertilizer. Since nitrifying bacteria are sensitive to Ph, temperature, light, and other factors, I'm wanting to monitor those factors so I can take appropriate action. Trying to do as much research on things so at least I can make informed decisions which is why I posted this thread. Maybe someone on this forum might be degreed in chemistry and biology and might be able to help guide me in this. I admit I'm a bit uneducated which is why I'm trying to learn more about this.

A little wide angle shot of the whole system. The valve and manifold assembly are just out of frame. Normally this is hidden behind stones like the ones in the bottom. I removed a few stones for this shot.

Guess you can say it works like an ebb and flow system except the water doesn't return to the reservoir once it's used for irrigation purposes.

 

[FountainMan]

The PH is currently 8.42, the temperature is 84.6, and the TDS (Total Dissolved Solids) is 636 PPM which is perfect. I'm just going to leave things alone.

 

[DirtMechanic]

That is one heck of a cool setup!

I had to look up N availability in pond water. .005 to .5 mL\L was discussed as median. 5 tenths to 5 thousandths is a pretty wide range. Will your bio filtration will reduce that number? Your pond water is showing fairly clean since tap water upper limits are 500TDS and that could be anything dissolved in there.

The point is I wonder if there is not much there for the bacteria to work with relative to the diet of fast growing veggies. Your system holds 102 liters and even if you had the high range pond water N available a under-informed guess would be 52 grams N. Thats 3 tablespoons and 1.5 teaspoons roughly. Were it miracle grow crystals at 24% N that is almost 15 tablespoons. It seems like you could see that much matter in the water. If that machine is scrubbing the water it will be far less. I bet the filtration really cleans it out though, so there is nothing much left to feed the bacteria.

I wonder too since the water is not being returned if simpler filtration would serve you better. You are after free fertilzer after all so why remove its source materials before fermentation? Or have a fermentation area that then pumps the now fertilized water into finer filters in front of the valve filters.

The pH can be dropped with nutrients like sulphur compounds. No biggie if you need it. Plenty of pH down products available from hydro sellers.

Fascinating rig. Thanks for showing it. I would love to know more.

 

[FountainMan]

That is one heck of a cool setup!

I had to look up N availability in pond water. .005 to .5 mL\L was discussed as median. 5 tenths to 5 thousandths is a pretty wide range. Will your bio filtration will reduce that number? Your pond water is showing fairly clean since tap water upper limits are 500TDS and that could be anything dissolved in there.

The point is I wonder if there is not much there for the bacteria to work with relative to the diet of fast growing veggies. Your system holds 102 liters and even if you had the high range pond water N available a under-informed guess would be 52 grams N. Thats 3 tablespoons and 1.5 teaspoons roughly. Were it miracle grow crystals at 24% N that is almost 15 tablespoons. It seems like you could see that much matter in the water. If that machine is scrubbing the water it will be far less. I bet the filtration really cleans it out though, so there is nothing much left to feed the bacteria.

I wonder too since the water is not being returned if simpler filtration would serve you better. You are after free fertilzer after all so why remove its source materials before fermentation? Or have a fermentation area that then pumps the now fertilized water into finer filters in front of the valve filters.

The pH can be dropped with nutrients like sulphur compounds. No biggie if you need it. Plenty of pH down products available from hydro sellers.

Fascinating rig. Thanks for showing it. I would love to know more.

Thanks.

The filter keeps the pond clean. The pond is home to goldfish and snails. Without the filter the pond does get murky. The filter is designed to remove the organic waste from pond water and expel it as effluent. The junk the filter removes from the pond water is expelled into the reservoir where it's further processed. It's not removing source materials prior to fermentation as those materials are sent to the tank along with the reject water from the pond. The pond water is cleaned, dirty water is sent to the tank. The fermentation occurs in the tank during holding periods between irrigation cycles.

There's actually a good amount of sludge and organic matter in the tank right now. That serves as the food source for the bacteria that break that down. I can tell the bacteria are working and active in this medium. When I turn the aerator off for a day then turn it back on, I get a bunch of hydrogen sulfide (rotten egg smell) for a few minutes before that dissipates. From my research online, when the oxygen is depleted in the water, the nitrifiers become anaerobic and produce hydrogen sulfide, nitrous oxide, and carbon dioxide. I was definitely getting that.

Right now, my main focus is housekeeping and taking care of the needs of the bacterial colony, which is why I began to track the temperature, PH, and TDS/EC. I'm even thinking about sending a water sample to Texas A&M AgriLife Extension for an in-depth analysis of the water's chemical and biological properties.

 

[FountainMan]

This is what the garden and pond look like without the stones pulled away. Everything above is concealed neatly within this. Unfortunately, the pond doesn’t have much aquatic plant life in it right now. Due to a ome personal situational issues, I wasn’t able to purchase pond plants this season when they were available at our local supplier.

A little tour of the entire garden,

The pond and garden during the day.

The pond and garden at night.

The west herb rail planter box. Have basil, parsley, oregano, and sage in here.

The middle planter box. I have chives, thyme, and purple basil in here. The east planter box is currently unoccupied. I have the irrigation line to that shut off as it would be a waste of water.

Our front door planter. About 50’ of tubing runs from that tank to this planter and feeds into the water feature in the front. The reservoir underneath the water feature is designed to be overfilled over the fill line where there are holes drilled in the reservoir at the fill line. When the reservoir is filled over these holes, water “overflows” out these holes into the surrounding soil, thus watering this planter.

As you can see, the plants absolutely love the “bio-water”.