Pond Boss Forums AERATION Systems questions Gast AT05 rotary vain

I am ordering a Gast at05 rotary vain for my 3/4 acre 10’ deep pond. Planning on 2 diffusers. Anyone think that is not a good choice of compressor?

Do you have a link to see exactly what you are getting?

Here is what I am looking at :

https://www.wholesalesepticsupply.com/pr...ASABEgJb1vD_BwE

I’m buying the tubing and diffusers separate.

That will be running it right at maximum allowable rated continuous pressure for that pump.

It likely will be ok, but the 10' depth is maxing out its capability.

I have no experience with that pump. Just looking at the 5 psi maximum pressure output in the specs.

I also am looking at Gast rotary vane pumps. They also make 0823 and 1023 series pumps which are capable of higher pressures (and cost more naturally). I'm in the same boat as you with about a 10' maximum depth (around 5 psi with any resistance in the line figured in).

It would be interesting to hear from anyone with experience running the pumps at near maximum capability and see if the life expectancy is good. I have been wondering if it would not be better to spend a little more for the higher pressure pumps that might live a little longer being run at less than maximum capacity.

I'm looking at a pump slightly higher in cfm capacity than I need for 24/7 operation, then put it on a timer to run less time, with hopefully about the same electrical cost.

Electric cost is nothing to sneeze at running continuously for 8 or 9 months of the year. I see guys talk about using pumps not made for aeration to save some money up front and wonder if they will not pay for the pump multiple times over by using lots more electricity by running efficiently.

I think the Gast vane pumps are pretty energy efficient when operating within their designed range of pressures.

Here is a place that lists a lot of Gast pumps in one place. I do not know if they are a good place to buy, but they have a lot of pumps to look at the specs.

I did notice that several call for a clean dust free environment. I like the idea of a TEFC (totally enclosed forced cooling) motor, which I believe from the picture the one you were considering looked like it was.

Place with lots of Gast pumps listed with links to specs

An interesting find. Been looking at the Gast 0823, 1023, and 1423 models of pumps,

They are rated 8, 10, and 13 cfm respectively, yet they all are rated at 56kw and pull about 5 amps at 230 volts. Hmmmmm. Weird.

So from strictly an electric standpoint, assuming all three would have one start cycle per day (where higher current flow for startup - running continuous it would not have that additional draw) it would be more economical to run the largest pump and run proportionately fewer hours per day, assuming the diffusers would stay within their operating parameters for cfm (or add another one or two diffusers if the larger pump had more flow than needed).

For example if the 0823 required 10 hours per day to get proper pond turnover, the 1023 could do it in 8 hours and the 1423 could do it in 6 hours 15 minutes. All with the same electric use per hour. So the 1023 should do the job on 80% of the electricity of the 823 and the 1423 should do the job on 62% of the electricity because of running proportionately fewer hours at the same 5 amp load.

Am I missing something? Seems strange. Seems like the higher cost of the bigger pump would pay for its additional cost in electric savings, not to mention longer life because it runs less total hours to do the job.

Gast rotary vane pump models

Edit: calculating electrical cost for above pumps assuming 7 days a week 30 weeks per year .08 per kwh. 0823=$148 per year. 1023=$118 and 1423=$92. Not as big of difference as I thought. In a ten year life span 1023 pump would save 300 dollars over the 0823 and should have longer service life. 1423 would save $560 over ten years and should have even longer service life because of reduced running hours.

Of course a person would have to figure in the cost of capital....... well maybe that is farther than I want to go. Looks like the bigger pump is not a bad way to go assuming a person can effectively utilize 13 cfm (actually a little less than that at depth).

Energy calculator

Edit: Ok, some of the above is wrong. Gast does a poor job of correctly listing the specs in their literature. On the main page all models are listed at .56kw although the 1423 is listed as a larger horsepower. Does not make sense because it is wrong. Downloaded the PDF data sheet and the 1423 is .75kw as it should be for 1 hp. So what I said above for the 0823 and 1023 difference holds true. The 1423 would use proportionately more electricity based on its larger motor. As it should. Be nice if they would get their literature correct.

The 0823 or 1023 pump run 27/7 for 30 weeks per year at 8 cents per kwh would cost about $355 to operate annually, if I figured it right.

FYI the mentioned Gast AT05-520-G215DX Rotary Vane Air Pump (1/4hp)is evidently for shallow septic tank systems and operates best at 5psi whereas the Gast 0523 model (1/4hp rated 5cfm open flow) operates at 10psi. I prefer the 0523-101Q-..... Evidently the air compression system is different in these two models. For pond use, I would buy one with the 10psi rating because this will put less mechanical stress on the air system and lengthen the time between rebuilds when operating at 10ft-18ft deep. IMO it is always good to have some excess pressure reserve for an aeration system. There are special times when it is needed/used during the life of the system.

I noticed those differences too and figured the same thing Bill. The only reason I saw that the AT05 cost as much as the higher pressure 0523 model is that the AT05 has a TEFC motor whereas the 0523 has a lest costly open frame motor. Otherwise you would think the AT05 should be a slightly cheaper pump yet they are priced about the same.

I looked for other larger models of the Gast rotary pumps with TEFC motors but it appears nearly everything (unless a mfg would spec it as a special order I suppose) in off the shelf models were open frame motors.

Not a big deal probably, the TEFC is just a more robust configuration for less than ideal environments.

the 0523 is definitely the better choice!!! Thank you.

Do a search for "Septic Solutions".

Or try this septic solutions

On the Gast site, AT series pumps are listed, with the AT05 having a 10psi continuous flow rating and a 15psi Max, yet the sites listing the AT05 for sale show a 5psi max and a max 4.8cfm air flow


If in fact the max PSI is only 5 psi, and If the diffusers are set at the max 10 foot depth, there will be just under 5 psi of head pressure, and the AT05 air flow will drop close to zero to overcome the head pressure....plus the vanes will wear out rapidly.

If the specs are as shown on the Gast web site, the AT05 will have ~4.1cfm@5psi and ~3.4cfm@10psi

FWIW, under the AT05 Spec chart, there is an AT05-101-G215DX listed with higher specs shown, yet in the Spec chart index, Gast shows the AT series to have a 5PSI max pressure, so I'm not sure what is accurate...(no AT05-520 series was listed in the spec sheet)

I have the AT05 pump, It has been running each summer since 6/15/2009, continuous except for the last two summers when I had it on a timer. My 1/4 acre pond is 12’ deep and I have one 4 head vertex diffuser in the center, off the bottom one foot.

It my pump is located on the second floor of an old farm building that is very dusty and warm. I have never done anything to it in 9 years but it stopped aerating yesterday, I’m going to rebuild it, the vanes are intact but very short and concave. Is 9 years good for vane life? I bought it from septic solutions that was mentioned above, they have a price match guarantee and also refund 25% of the difference.

I think the bacteria did a better job when the pump was run continuously. I would like to replace my 4 head diffuser with two 2 head diffusers, did somebody say splitting them up will use the same psi’s? Is that correct?

What pump did you end up with DRG?

I ran into some conflicting specifications in several places on the Gast site. It left me wondering which was correct or if there were specific sub-models that the different specifications matched.

It was a little confusing at times, but I still got enough information to suit me.

So far I am very happy with the Gast 1023 pump which has been running several days now. I'm running it about 7 hours a day currently. If it lasts as long as Loretta's before rebuild I will be tickled pink.

I found a lot of inconsistencies in the literature when I was looking to buy one too. I think I saw 4.8 cfm on the pump but I’ll have to look again.
I found the rebuild kit for $58 with free shipping and It seems easy to do. Good to know that I got decent mileage out of it. I really neglected the pump and I’m going to try harder to check filters.

Help me with this. The Vertex brand 1/4 hp compressor (don't know who makes it) is only rated for 2PSI. You are raising concerns about 5 psi not enough in a 12' depth. How does the Vertex brand 2 diffuser head setup at 2 PSI say that it is rated for 30' depth and 1.5 acre pond?

Vertex pondlyfe 1

i can’t answer your question Canyon, I just know my pump has been sufficient for my needs and I think it’s rated different than the one you linked.

canyon, I believe the pondlyfe system uses a piston pump that is rated much higher than 2 psi. The confusion may be coming from all the "2"s in their specs...

2 CFM,
2 amps,
and I think you will find that the vertex double diffusers require 2 psi to operate.

If the pump can handle 30 foot depths, that tells me it can put out around 15 psi.