Aeration design for RDWC

[aSilvrHaze]

I'm setting up a 4 site RDWC (UC-style) and am down to designing how the aeration is going to go & I'm scratching my head a bit. I want to use an AP-100, and the flexair discs in all buckets. What I've had in mind the whole time I've been planning my setup, was to basically make a manifold to distribute the air to each site. The pump has a 3/4" outlet and I was thinking of hooking that up to some 1" pvc and then T off to each site and reduce down to 3/4" at the bucket because the flexair discs have 3/4" connections.

Basically, my goal is split the air flow about as evenly as possible. The pumps output is about 5 cfm. And each disc flows .5 - 2.5 (low flow disc) and 1 - 4 cfm(high flow disc). The spec is actually SCFM but I'm pretty sure its about the same as CFM. And I read that they perform better at the lower end of the spectrum so if each bucket gets an even amount, they should each be getting about 1cfm, right?

Does all this sound semi... reasonable? lol Am I making sense? Or just over thinking the Sh!t outta this. Care to share your .02?

 

[Papa]

hey bro, that all sounds good. the 100 may be a bit too much, you may want to include a blow-off valve on the line to dial it down if you need to.

the other issue will be holding the discs down when they're buoyant. giddeon came up this "air basket" idea that i'm running also:

those disks really wanna float when they're filled with air!

also, i find the ceiling is sometimes a good place to run those airlines.



Papa

 

[aSilvrHaze]

they want to float even with it being connected to the pvc inside the bucket? That was another concern I had, but I thought that being connected to a rigid piece of pipe would hold it down decently.

 

[Papa]

i don't know how you're planning on bringing the air to the diffuser, but i suggest with all details like this, mock it up. nothing better.


Papa

 

[ALLegal420]

Papa, does air just run thru the disc or are there some ports on any of the pvc piping?

Looks like an awesome setup... do you know if the 4" Ecoplus air discs want to float as well?

Haven't seen your style of air disc before, time to do some more reading...

 

[Papa]

no ports, all the air comes outta the rubber top surface of the disk. these disks are 9". dunno what the 4" does.

in this setup i wanted to run the airlines on the ceiling and come down into each tote. i first thought that i could use glue to tack some zip-ties to the tote and tie down the pvc and disc. it was a no go. as soon as the air filled up the disk the glue couldn't hold it. i've found that mechanical fasteners are oftentimes better than chemical . . . so i jumped on this mechanical solution. the weight of the plant holds the disk assembly down in place . . . and the disk assembly helps to support the lid when it strains under the weight of the plant.

the air in the pvc adds to it's buoyancy, so i minimized this by using 1/2" for the "basket" and increasing it to 3/4" to connect to the disk.

these flexair discs are highly efficient at making tiny bubbles. they are commonly used for aeration in wastewater treatment. here's a pic of a typical application in a wastewater basin:

 

[aSilvrHaze]

yea it was a toss up between these and the oxygen shields, but they're around the same price so I'm sticking with my original idea of the discs. My idea for bringing the air to the diffusers is basically the same as the connections for the main pvc lines in the buckets, DIY bulkheads using electrical conduit fittings & o-rings.

 

[Kasi]

UC answer between O2 shield a 9" disk

UCHQ answered a similar question I had about the air defussers and the UC systems. in here Post UC Questions and Concerns Here

Have a nice day:hi

 

[ALLegal420]

Thanks for all the info, I'll be watching what our stuff does when we do a dry run here pretty quickly.

I like the idea of it also supporting the weight of the plant, anything helps and 1/4-1/2" sag could affect numerous things if not caught ASAP.

-ALLegal420

 

[lava]

anyone running the 9" or 7" diffuser under each plant? I want to do this, but im concerned with the height that the diffusers will take up. In my diy uc, the highest point of the diffuser will sit 2" below the netpot when inflated and .75" below the water level.
Will it aerate and move enough water sitting that high? Will it disturb the roots too much being that close?

 

[Papa]

lava, imho i think that's too close, it'll disturb the roots too much and not provide the aeration you're seeking. the amount of aeration these units can provide is based upon the contact time of the bubbles in the water . . . the deeper the water, the better.

 

[lava]

ok, so the round diffusers will not work for me.
Has anyone tried the tubular diffusers? Since the hose connects from the side, they will sit lower.

*In testing, these air diffusers produce a slightly larger air bubble than air stones which translates into less oxygen transfer into the water, so for fish holding tanks, raceways, fish productions ponds, etc. we recommend staying with the air stones.