Trough aeration increases plant growth!!

[Chris Smith]

I have seen several aquaponic farms in the area that have been adding supplemental aeration in their troughs and getting dramatic increases in plant growth in the immediate area of the aeration. Seeing this happen has prompted me to add aeration to my troughs. I just got done running main lines with a blubber every 4 feet in my troughs. I hope to increase my plant growth with the extra DO.

I plan to add an air stone every 2 square feet in my micro system as experiment to compare to the commercial system.

My current theory and direction are going toward a low water transfer of about 2 gpm through the troughs and high aeration. I will down size on the water pumps and add to the air pumping capacity. My electricity costs $.44 kw hr so I want to get the systems as efficient as possible.

 

 

[Green Acre Aquaponics]

Kobus, the aeroponic set up would definately cost less, but it would have no benefit as a biofilter for the fish.
We would like to add this into our system somewhere in the future, but it would only be for fun!
Kobus Jooste said:

I have been following this discussion for a bit and want to throw in a question.  If the rafts benefit from having oxygen and water in contact with the roots, what would cost more and work better: submerged roots that are aerated, or having spray bars in the raft structure that are pump driven?  Obviously with the latter, if there is a power failure, the roots will be at risk of drying out, but I was wondering about the viability of modified aeroponics on a large scale

[Green Acre Aquaponics]

Chris, we took a reading of about 4ppm in our troughs before adding the air. Our troughs are 48ft long and we have 6in medium pour stones in the middle at every 4ft. We now have readings around 11ppm.We would like to get up to about 28ppm, we have heard the growth of the plants explode at that level but we have to purchase a larger pump for that!
Chris Smith said:

I have not taken any readings since adding the bubblers. I just finished the project yesterday. The last reading was 4 in the troughs so I assume that it is higher now. I do not own a digital meter but can borrow one again soon. I was using a test kit that involved lots of steps and many drops. I found that it was not accurate when compared to the digital meter. My plants were growing fine with the DO at 4 but I want to increase the growth rate. I diverted some of the air that was going to my fish tank over to my troughs. I used many small bubblers and each one has a 1/4 drip irrigation valve so I can adjust the amount of air at each stone. I did not add any extra air pumping capacity. The fish seem to be fine. Their tank is now a mellow jacuzzi. It seems to be enough air and water moving to break down the solid waste.

Ryan said:

And Chris, have you taken any DO readings(before or after the addition)?

[Green Acre Aquaponics]

Michelle, the fish should have at the very MINIMUM and this is pushing it 4ppm in the tank. At 6ppm they are comfortable. We are running between 8.5 and 9ppm. Keep in mind also that the water temp plays a factor too. Cooler water holds more dissolved oxygen than warmer water, so in summer, you might need to adjust the air up.
And I read somewhere, (so don't quote me on this) that DO at or above 12ppm for the fish can cause eye embolisms.Michelle Silva said:

"Water pumps generally take more electricity to run then air pumps"...? The water pump I have from Aquatic Ecosystem uses 95 watts of energy (950 GPH). Cost was around $100. I was originally advised that I needed to have an air pump and air stones when I was first setting up from a few others... didn't get one because the ones I found were so expensive, plus the addtional cost of all the air stones and thought I would try first to see how well it works without.

I'm curious what the DO is at and will be borrowing one soon to check. What is the preferred DO level?

Ryan said:

I would look at the fact that there arent any commercial aeroponic farms in the US as a sign that the technology hasnt been refined enough. You have to have a high pressure pump to force the water through a fine filter before you get to the sprayers or they will clog. With hydro, cleaning the filters is not quite as burdensome but with AP, you have a lot more solids to deal with. As you mentioned, you also have the chance of total crop failure if the filters clog or the pumps stops.

Water pumps generally take more electricity to run then air pumps. If you want to eliminate one of the pieces of equipment, you can run air lifts instead of a water pump and use a single dedicated pump/blower for your air source.

[Green Acre Aquaponics]

Ryan, I am just curious, did you take a course at Morningstar Fishermen in Florida?

Ryan said:

I would look at the fact that there arent any commercial aeroponic farms in the US as a sign that the technology hasnt been refined enough. You have to have a high pressure pump to force the water through a fine filter before you get to the sprayers or they will clog. With hydro, cleaning the filters is not quite as burdensome but with AP, you have a lot more solids to deal with. As you mentioned, you also have the chance of total crop failure if the filters clog or the pumps stops.

Water pumps generally take more electricity to run then air pumps. If you want to eliminate one of the pieces of equipment, you can run air lifts instead of a water pump and use a single dedicated pump/blower for your air source.

[Green Acre Aquaponics]

me too!

Michelle Silva said:

I'm interested in learning more about this too..sounds great.

Chris Smith said:

 

Aloha Alan, I have been researching how to make an add o miser to increase the DO in my system for a while now .Do you have any links for designs or units for sale? I really like the idea of micro bubbles around the roots of my plants!  I am sure it would promote very rapid growth.

Chris
Arik Alan said:

Chris, have you explored the use of an add o miser for increasing DO in water?  large air pumps take a lot of power to operate.  an add o miser may not increase operational cost outside of cost of materials.

[Rudy S]

11ppm? What altitude are you at? That should be fully saturated. Check this chart. Even if the charts wrong, Ive never heard of 28ppm... Are we talking about oxygen?

http://www.hakkoairpumps.com/subcat15.html

[David Hart]

Randy, they are in FL.

lol...We have the 'lowest' high point, in the nation......the highest point in FL is 345 feet, but that's in the panhandle. The av. elevation in FL is 100 ft.

Rudy S said:

11ppm? What altitude are you at? That should be fully saturated. Check this chart. Even if the charts wrong, Ive never heard of 28ppm... Are we talking about oxygen?

http://www.hakkoairpumps.com/subcat15.html

[Ryan Chatterson]

"Ryan, I am just curious, did you take a course at Morningstar Fishermen in Florida?"

No, Ive heard of it but never really saw the need to travel over and pay $$ for it. :)

[Rudy S]

I had a sneaky suspicion that the black thing on the atomizer was a UV light, now I know.

http://www.marineandreef.com/Emperor_Aquatics_Smart_UV_Sterilizers_...

I also found another atomizer, I emailed them for a price. I really think this is the way to go for aerating alot of water

http://www.emperoraquatics.com/commatomizer.php

[Rudy S]

Arik Alan:

 

In the picture you posted where you had added the blue text, where did you get that info?  Because Im thinking the 4" PVC that you listed looks more like 6"

 

Just tryin to figure this all out so I can make one. the emperor aquatic one looks complicated but probably works great

[Marina Galvan]

Check out the bottom of page 81 in the Aquatic Eco Systems catalogue. It shows a small table of oxygen saturation at different temperatures. For example, at my average ambient water temperature of 75 degrees farenheit, saturation is 8.4ppm. We've got around 7ppm, so there's still some room to improve.

[Green Acre Aquaponics]

Yes, we actually just got a nifty little ruler from them last week that has O saturation levels on it.  We are currently running at about 100% saturation.  When we first added air to the troughs, it was with 11( at 4ft intervals) small, 2" medium pore airstones.  We ran short and had to use a few of the 6" we had.  After seeing the difference in the plants that were in the vicinity of the 6" stones, we decided to switch all over to 6".    We actually have to play with it a little and see if we can back off our air flow  and still keep the saturation level, as we need to divert air over to our nursery tanks soon.