AeroVoir watering

[lynnnoelle]

I have tried this setup using n 8-QT food service canister for the bottom, and a 4-gallon water jug from an automatic dog water bowl setup. The cap to the water jug came with a charcoal filter at the outlet which I removed. I taped over two of the exit openings, where the water usually comes out. There is also a small hole in the side of the cap (which is about 3" tall.) The siphon tube exits the lower canister below the surface of the water, near the bottom. I had my husband silicone heavily around the hole so it is water tight and doesn't leak. I initiated the siphon action and determined the proper water level for my Bounty. To test it, I filled my Bounty to the Medium mark and got it going. All appeared to be good and the siphon system filled the Bounty to the appropriate level.

The problem is that the setup seems to work for a few days, and then stops. I cannot figure out why. If the system is set up and has stopped, if I clamp the siphon tube, take it out of the Bounty, and place the end in a basin, the water starts moving again. I noticed in your setup that the siphon tube enters the lower container above the water level, and then down to the bottom of it. Is this absolutely necessary? If so, why. Also, in your setup, the upper jug contains only one whole for water to exit, is that correct? I'm trying to figure out if that's why my setup doesn't work. In the cap of my 4-gallon jug, there is a small hole in the side of the cap. Maybe I should plug that. I tried to attach a picture here, but the file is too big.

[lynnee]

scarfguy and maskedsonnet know more about assembling a self-watering system than I do, and may have some suggestions.

[maskedsonnet]

You may be having enough air bubbles forming in the tube to stop the siphon but not break it completely, so when you lower one end it starts back up. And while there are two leading theories on how siphons work, the scientific community can't actually come to a complete agreement on how and why they do what they do. That being said, in my mind the setup I have is necessary. From the above article:

A practical siphon, operating at typical atmospheric pressures and tube heights, works because gravity pulling down on the taller column of liquid leaves reduced pressure at the top of the siphon. This reduced pressure at the top means gravity pulling down on the shorter column of liquid is not sufficient to keep the liquid stationary against the atmospheric pressure pushing it up into the reduced-pressure zone at the top of the siphon. So the liquid flows from the higher-pressure area of the upper reservoir up to the lower-pressure zone at the top of the siphon, over the top, and then, with the help of gravity and a taller column of liquid, down to the higher-pressure zone at the exit.

To me that says this type of setup:

is necessary for a siphon to continue flowing, even if the reservoirs are actually on the same level instead of one elevated. The "elevation" in the case of our DIY AeroVoir is achieved by a top reservoir feeding one side of the siphon. Why won't it work with the tube at the bottom? You've got me there!! Fluid dynamics never was my strong point.

All that to say - I can really only make wild guesses at why your system spontaneously stops working. Sorry  

[lynnee]

Fluid dynamics are definitely not my thing, maskedsonnet , but your explanation is quite helpful.

[lynnnoelle]

Thanks for the response! Getting this system right has been a frustrating experiment, for sure. I'm going to try drilling holes above the water line in my 8-Qt bottom canister and see if it works. 

[lynnee]

lynnnoelle, here is a rather long YouTube video on setting up a watering system that may help with troubleshooting your system.

[agnoob]

Hi fellow Aerogardeners! I’m new to hydroponics but so excited to get started with the five gardens (from three harvests annd an bounty all to way to a farm 12 XL) I bought on Prime day. I’m going to be on two separate vacations (9 and 12 days) in the next several months and want to start planning ahead. I ordered reservoirs based on maskedsonnet’s setup:

Set of 2 - BPA FREE Water Dispenser Base with Spigot & 5 Gallon Water Jug Set - Transparent Blue - For Countertops or Stands - 2 Complete Sets a.co/d/8y98nFh

My question is:
Should I add nutrients to the reservoir for when I’m gone - I’m worried that:

1. it’d over feed the plants with nutrients and
2. cause algae growth.

On #1, did your plants do okay with or without new nutrients when you’re away for two weeks? (For context, I’m growing herbs, greens, tomatoes, cucumbers and ground cherries)

On #2, I’ll try to prevent algae growth by adding hydrogen peroxide to the water, covering the reservoir with black cloth, and using black tubing. If you’ve added nutes to their reservoir, what’s your experience with whether you get algae?

Thank you so much in advance!!!

[maskedsonnet]

I never add nutrients to the reservoir, only to the garden itself. That would over-feed the plants and cause algae problems both. If you’r a bit early or late on feeding it’s never seemed to hurt my plants (depending on HOW early, you don’t want to do more than a few days without reducing the amount), they’re on a 2-week feeding schedule with AG nutrients anyways.

When I’m gone for long periods I may hold off on feeding until right before I leave, I have been gone for 2 weeks many times with no problems if I know I’m going to be gone and prepare ahead of time - make sure all your bottles are topped off, feed the day before you leave, and have fun while you’re gone!!

Ive been up to a week late with nutrients before, and while it stunted their growth a bit it didn’t kill the plants, or even make them wilt. If you’re a week or more EARLY feeding them before you leave though, give them half (or less) of what you normally would so you don’t over-feed. For me that’s always been the quickest way to accidentally kill my plants.

[agnoob]

maskedsonnet Thank you for the detailed reply! Super helpful. I’ll definitely keep that in mind when planning the feeding schedule ahead of vacations.

Also thanks for the DIY reservoir idea in your previous post too! I’m thinking I’ll have one 5 gallon reservoir feed into a Bounty and a Harvest. Do you know if having two different sized grow bowls be fed from the same reservoir causes any overfilling in the smaller bowl?

[maskedsonnet]

Nope! The different bowl sizes won't make a difference, it's all about the water level. I've actually got a 3-gallon bottle feeding a Harvest and Bounty - the water levels are just right for both machines that you shouldn't have to elevate one, looks like we've got the same bottom reservoirs. Just double check to make sure the level in the bottom reservoir's not above the fill line of your machines. The only garden I've ever had to elevate to prevent over-filling is my Sprout, which is so small I just hand-water it now instead of using an attached reservoir.

[agnoob]

My 2 reservoir sets have arrived! I got black potato grow bags to cover them to prevent algae growth. I love that potato bags are cylindrical and come with a velcro flap. That way I can lift the flap up to check the water level without having to take off the entire cover and exposing the water to light.

10 gal potato grow bag for the top (This one has 5 draining holes at the bottom which I covered with black electrical tape)

7 gal potato grow bag for the bottom

Reservoir set (also comes in 1 pack by the same seller)

[agnoob]

An update on my new reservoirs:

I had one of them connected to a Bounty, a Harvest XL, and a Harvest . All of them were on the same level. The Bounty and Harvest XL were filled right up to the max fill line. However, the Harvest was overfilled right up to the grow deck so I didn't realize it until a day has passed. I got rid of the extra water from the grow bowl and propped up the Harvest so that it only gets filled to the max fill line but it was already too late. My two 3-week old AG heirloom cherry tomatoes now have many blisters on their main stem and at least one leaf on each is yellowing and also have blisters. I think it's edema from being over-watered. Do folks think my young plant will come back from edema if I fixed the water issue within a day?

[scarfguy]

agnoob said, "Do folks think my young plant will come back from edema if I fixed the water issue within a day?"

.... .... YES!

[lynnee]

agnoob, how are the overwatered tomatoes doing now? Probably just fine, as edema doesn't usually kill a plant.

[agnoob]

Unfortunately the tomato plants didn’t grow more new leaves. They did start growing flower buds. I think there was a viscous cycle here: the growth of the young plant was stunted by edema -> this leaves the grow sponge exposed to light for a long period of time due to lack of leaves shielding the sponge from the light -> algae started growing rapidly on the sponge which further stunted the growth of the plant. Yesterday I made each plants into a cutting and planted them in the smallest Kratky jars possible (2 oz moonshine sample jars). Fingers crossed that the plants would start rooting now that there’s no algae in the jar. I also put them both under the Farm’s strong grow light so hopefully that’ll also help.

(I finally figured out how to embed image links! So here's a pic of the mini Kratkys - see my ground cherry seedling in the background to get a sense of how small the tomato cuttings and jars are)

[agnoob]

I also found a different issue with my DIY reservoirs. I added hydrogen peroxide to the water to prevent algae. This produced some air bubbles that have nowhere to go except for the airline tubing going into the grow bowls, which means the siphon wasn’t working since the bubbles blocked the water flow. I’ve drilled a few holes on the bottom dispenser hoping that would be enough of an escape for the the bubbles from hydrogen peroxide. I have yet to test if that did help. If that still doesn’t do it, I’ll just go with plain water for the reservoirs. Since I cover them completely with black potato grow bags and use black tubing, there’s low risk of algae growth anyways.

I also used hydrogen peroxide in the water in an Aerovoir. I’ve since learned that the bubbles generated would cause the aerovoir to slowly leak a lot of water between the tank and the stand. At first, I mistakenly thought I had a defective unit and AG sent me a replacement one. I now learned that it’s just the peroxide and I have an extra Aerovoir for free. Whoops. So instead of peroxide, I’m just covering the tank with a reflective gift bag from the dollar store and taping black electric tape over the tubings to prevent algae growth.

[lynnee]

agnoob, I'm not sure that the blisters on your tomatoes were edema. Edema produces white ir yellowish crystals that can join up to create something that looks like a growth, but I've only seen edema on plant leaves (not the stems).

Keep us posted on how the plants do as cuttings. I'm wondering whether they may have some sort of virus or fungus.

[lynnee]

agnoob, did you try pumping the hydrogen peroxide bubbles out of the Aerovoir with the squeeze bulb? That always works for me, but I do have to keep pumping for a bit. Bubbles can be stubborn about clearing the bend in the stiff plastic connector to the tank.

Some of my Aerovoirs leak a little in the bulb area. I put a thick washrag underneath the bulbs to take care of this. I have no idea why adding hydrogen peroxide would make your Aerovoirs leak.

For some reason, I never get algae in the Aerovoir tanks or the AG gallon jugs. I think that the pale blue color of the plastic offers some protection. You seem to have solved the issue with algae in the reservoirs by covering them. Do keep us posted if anything new develops!

[agnoob]

I did use the pump for the aerovoir - that did get rid of bubbles in the tubing but not in the tank. Hydrogen peroxide continuously forms bubbles so it’s not a one-off, pump-off-bubbles kind of thing can resolve once and for all. (I’m a chemist by training so I’ve worked with peroxides before.) The continuous bubbling inside the tank exerts pressure onto the tank’s cap and lets out extra water into the stand. That’s what’s causing the leak between the tank and the stand.

[lynnee]

Aug 24, 2023 11:53:08 GMT -5 agnoob said:

I did use the pump for the aerovoir - that did get rid of bubbles in the tubing but not in the tank. Hydrogen peroxide continuously forms bubbles so it’s not a one-off, pump-off-bubbles kind of thing can resolve once and for all. (I’m a chemist by training so I’ve worked with peroxides before.) The continuous bubbling inside the tank exerts pressure onto the tank’s cap and lets out extra water into the stand. That’s what’s causing the leak between the tank and the stand.

How interesting! I always want to know the "why" and "how" of things!