Pond Boss Forums AERATION Systems questions Gast Pump CFM question

Hello all,
I have a Gast Pump Model 6LCF-13-M616X and was wondering how many 9" disc diffusers I can hook up to this baby. I would be placing the diffusers in about 12 feet of water using 400-600 feet of 1/2 inch polyplastic tubing. Thank you for any replys.

Bob

I found a spec sheet on the pump and here is link:
http://gastmfg.com/pdf/piston/specsht/6h6l.pdf

It will do about 6.3 CFM's at 50psi according to the spec sheet. The diffuser that I have is from Diffuser Express (part number 01798): http://www.diffuserexpress.com/catalog/flexair_threaded_disc_diffusers.html

This is a 9 inch disc with a design airflow of .5-5 cfm's. I am wondering if .5 cfm is what I would use to calculate how many diffusers this pump will handle?

The way I calculate it this pump can handle 12 diffusers. Agree?

Bob,

How big is your pond? In my case, I have 2 diffusers in 12' of water on a .75 acre pond using a 1.5CFM pump. My pump is only about 75' from my diffusers. Ideally, I would like a little bigger pump(2-3 cfm) with the same number diffusers although this has worked great for the last 3 years. I would think you would have some cfm loss in that span of pipe, not sure how much.
Depending on all the above, I would probably max on 6 diffusers.

BarO,
My pond is about 15 acres. Actually it's a small lake:

http://www.rvanorman.com/images/gallery.asp?foldername=/images/lake

Notice in the pictures that the weeds are a serious problem. The muck is very deep. Great bluegill fishing though! My goal is to remove the muck and make it deeper to avoid some of the weeds. I've been reading here on Pond Boss for about a year now on Aeration and the benefits of it. Currently I have 8 diffusers running on a Gast pump 0526 with a 2/3 hp motor. That seems to be doing fine with 8 diffusers, but don't think I could add anymore to that system. So I got this Gast Pump Model 6LCF-13-M616X to add to the project and add some more aeration.

I'm the guy holding the lake weed cutter gadget I made from a hedge trimmer.
http://www.rvanorman.com/images/gallery.asp?foldername=/images/lake

Thanks for any feedback.
Bob

Bob,

I'm certainly no expert but here are my thoughts. If your intent is to maximize the number of diffusers, you should give some thought to the effect that pipe size, pipe length and water depth will have on available scfm from the compressor.

Hopefully the experts will offer better guidance.

Russ

For the minimum of a good circulation for a 9" disk diffuser I like to try and get 1cfm to each. Less cfm per diffuser will create a boil but I prefer around 1cfm to adequately mix the water in the zone of water around the diffuser.

Thank you BarO, Rus, Bill, for the great info. I will try to keep it close to 1 cfm per 9" disc diffuser. After all, the purpose of aeration is to mix the water to increase the oxygen levels at the bottom where the muck is.

I will get some pictures and maybe some video of my aeration system over this holiday weekend and post them here. I'm always interested in what others have done to improve the quality of water in thier ponds. It's also fun to share in the projects that I'm doing as well. I will post some pictures this weekend. Thanks again!

Bob

Beautiful lake Bob. Looks like a great place for the family. I have a question. Do you plan on clustering the diffusers or spreading them out?

Thank you for the kind words WaterWizard. Yes indeed, it's a great place to have a family. We live here in southwest Michigan on 50 acres and we really feel blessed to actually live here. The lake is about 100 feet out my back door.

I plan on distributing the diffusers throughtout the lake. Currently I have 2 clusters with 4 discs on each of them. I'm planning on 2 more clusters of the same. Here are some pictures of the diffusers I made:

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=122245#Post122245

I'm a DIY kinda guy. It's funner that way.

Bob

Bob, If you are clustering the diffusers in groups of 2 - 4 then I think you could try for 0.75 cfm to each diffuser in the cluster. Try not to get the diffusers too far apart because that will create separate boils at the surface. If you are seeing or can recognize the separate bubble patterns at the surface I think then that they are too far apart and not working as a combination together to crate one enlarged upwelling of water. IMO separate boils from a ganged diffuser are less efficient than one combined larger upwelling boil that has merged from 2-4 diffusers.

Bill, I will take a closer look at the boil to see if I can recognize a separate bubble pattern at the surface. The diffusers are 6 inches apart from each other or about 18 inches center to center of the diffuser. If I can identify a bubble pattern at the surface of the water I will build them closer together on the next system. Thanks Bill for your willingness to share your expertise. I'll post some pictures this weekend as to the progress. Thanks.

Bob

Six inches apart should be okay and produce a solid pattern of bubbles at the surface. The shallower the diffusers are set the more likely the bubble pattern will be separate. Others may not agree with my philosophy on this concept. I have no proof or test data that my theory is correct. It just makes sense to me that combining the flows will enlarge the total boil and enhance the total upwelling affect. I think that two or three boils close together yet separate would produce some turbulance that would in the end work against the other boil upwelling.

Good info, with which I totally agree. I have photos of my new pond, and po boys co-active diffuser setup.I will post some day. It works so much better than 2 individual ones. Good advice from the pros, as usual.

On a side note, the boil attracts BG which in turn attracts the pond predators. In the evening when I am feeding, I will notice quite a bit of activity around the boil. LMB sometimes leaving the water in pursuit of a meal. I have also caught all sized BG with my flyrod by tossing grasshopper flies around the boil.

In my old pond, the shiners would school up in the bubbles. Late evenings, they would all go airborn simultaneously to escape the bass.

I once told a customer that if he did not catch a fish on the first cast into the boil of our system that I would give him $100. Result: First cast 2 lbs LMB, Second Cast 2 lbs BG, Third Cast 5.2 lbs LMB...and Fourth cast on his son took over.

This is an AP5 system on a lake front property of a 500 acre lake. He said that when he wakes up on the weekends the weekend worrior fishermen are around his boils catching fish off their $30,000 bass boats. He only spent a couple thousand to do that right off his dock.

The boil not only creats circulation which the fish desire, but the boil also creates ledges for the preditor fish to hide, dart out and attack. See photo below and how the ledges are created.

Also the upwelling of aeration boils bring to the surface lots of zooplankton that typically inhabit the deep darker waters during the day. Larger zooplankton spreading out away from the boil serves as a food buffet for esp the smaller fish that thrive on zooplankton. Larger fish are attracted to the boil to feed on small fish busy eating zooplankton.