Pond Boss Forums AERATION Systems questions High volume linear compressor lower elec. bill?

Easy Pro makes a high volume very quiet diaphragm linear compressor that produces 4.7 cfm's of air at 8 feet with power comsumption at only 125 watts. If my calcuations are right that's only a little over $8.00 per month in electricity vs. my 5 amp. 1/3 H.P. Gast rotary vane compresser that produces about 4.2 Cfm at about $25.00 per month.

I need one more compressor of this size to aerate three very small ponds and and to aerate a tank of well water to really agitate it to precipitate iron faster.

Anyone know if I would I have any problems hooking up four outlets to this as I do with the rotary vane compressor in another larger pond on the property? My only concern is if it has enough pressure to push the air to three ponds and the tank. The tank will only be three feet deep and the ponds a max of 9 feet. The compressor is rated to a max depth of 9 feet.

Price is higher but 6 to 8 years use is supposed to be the norm for these, and if they are this efficient, and long lasting I would be willing to pay the $419.00 (wholesale)

Comments?

Hi Cecil, If you have the 2005 Aquatic Eco System Master Cat look on page 255 The Sweetwater SL 94 is rated 15 ft depth,90 watts and 4.2 CFM for $380.00 Their toll free is 1-877-347-4788 if you need a cat. They have an online store also. Give them a call with your situation as they know linear pumps very well.I dont think you will have a problem with your described situation.Tech support is 407-886-3939 Apopka Fl Bob Heideman > President The Gast 0523 comparison today is the same CFM as before but still in the 4.2 amp range so a linear will run for less.The 0523 can be had for the $245.00 range low or high volt. Take care Ted

TLG,

Thanks I do have several of their catalogs. I guess I just assumed they were more expensive and didn't bother to look. Great catalog but some of the items are much higher than other suppliers.

I'll take a look.

TLF,

Yes I checked. Thanks! Looks like I could get over 4.2 CFM with the SL94 and only spend $5.76 a month for electricity. Even even if I went with the SL170, and get about 6.5 CFM I would only be paying $8.96 in electricity vs. about 25.00 per month for with the 1/3 hp. HP Gast. Initial higher cost is less relavent than long term efficiency to me.

One more benefit. I have a neighbor who is a cop within about 200 feet of me that complained about the sound of one of my other diaphram compressers as he leaves his windows open in summer and works a night shift. Sounds like these linears are pretty quiet.

Thanks for the heads up!

For those of you new to this forum, or not familiar with Ted Lea, he makes his living selling pond aeration equipment, consulting services...

Noticeably absent from this and many other knowledgeable posts from Ted, and others pros, is any solicitation for business. On the contrary, he possibly saved Cecil a hundred bucks on a pump, as well as providing pertinent information on where to source it.

Remarkably this forum is filled with information, unselfishly contributed by profesionals, soley for the benefit of me(ignorant masses). Was going to say "us", but didn't want to include everyone in the "ignorant masses" category. Even though most of you are.

Thanks to all!

The Sweetwater SL 94 has a performance graph at the following website: http://www.fishfarmsupply.ca/linear_Piston_air_pump.htm It looks like the CFM falls off pretty quickly as PSI increases. It looks like the 4.2 CFM is at zero PSI and zero CFM at 7 PSI.

Gumboot,

Good point. Even though TLF doesn't sell that particular pump he still unselfishly offered information. Hats off to TLF!

Cecil and Float, Yes the back pressure is the starting point on the calculations on a linear pump, This is why often Airstones vs rubber membrane diffusers are used with linear pumps in shallow water and often a coarse stone used vs a fine.(less back pressure) but less vertical current too. (not always good)The 4.2 CFM is open flow and calculate 1/2 lb of psi required per ft of water depth.Instead of trying to put a pencil to it I would run your depths and hose lengths past AES and they will give you the output and perhaps the turnover. I would assume you want to maintain 70-90% saturation in the summer months for your operation.If I ever need stones for slower turnover or a given situation I use Great lakes or sweetwater glass bonded silica stones from them.Hope I did not mislead, Ted

So I may not get the same boil with the linear vs. the rotary vane? Was this energy savings too good to be true?

I guess I'll have to give AES a call. I have noticed though some techs are better than others. One tech was previously in sales and as far as I was concerned I knew more than she did.

Cecil, I have reread your original post 3 times and it is the same each time I read it as 3 small tanks at 3 ft and one 9 ft depth the first time.(Feb 25th)>>must be the cold medicine)Your 3 ft depth obviously 1.5 psi is not a problem and perhaps 3 of them would not of been a problem and then AES would of confirmed the result of the single 9 ft depth in conjunction. Since this is not the case that linear pump (SL 94) wont work.More reason to run your numbers past your aeration supplier for confirmed results.Even if you were able to squeeze some air to 9 ft it probably would not be enough and very difficult to keep regulated. I do not know your pond size but believe you have stated in the past they are small and intense.Do you know how much air you want/need in the 3 nine ft ponds. The max I would figure is 2200 gallon per minute turnover at 1 cfm for each pond. This may be more than you want.Do you know what your current diffusers are turning. If not when you did a DO check in warm water on a cloudy day and have a 7 mg/l (or ppm) reading or maintain 80% saturation regardless of temp your diffuser/s are doing OK. GENERAL RULE for most pond that if you are not turning a minimum of once per day (entire water body)you arent aerating properly or lets say receiving all the benefits aeration should/ can provide.If that Easy Pro is 4.7cfm at 8ft and not open flow I could see that working depending on the "back pressure" not "pressure" of the diffuser. The diffuser pressure will be just under 5 PSI.Calculate about 1.5 PSI to overcome hose friction loss and most checkvalves at that depth no matter if its a stone or a membrane diffuser.The exception would be a fine airstone or a membrane diffuser that was slotted with less than 6500-6600 slits per 9 inches of surface. (we wont get into I slits VS Y slits and .5 mm holes VS 1mm holes) The Gast you have now at 1/3 HP has been replaced by a 1/4 HP model and pulls about 4.2 amps but will give you 4 CFM at 9 ft, model 0523.Still 4.2 CFM open flow.I looked in a Stoney Creek cat for that Easy Pro spec but did not see it.I size to maintain at least 80% saturation and or 7-8 ppm minimum DO. Trout water and various other cool waters can be a problem with this formula but slowing up the circulation to maintain cooler water and attaining a higher % saturation of the cooler water seems to work just fine. Trout goal is 10 ppm and the opposite is carp that can survive on 1-2 ppm DO, Ted

One last item Cecil, you mention "boil" and that is a good term. One of my displays is a 1.6 CFM piston pump that is manifolded to each a 7 inch round airstone a Great Lakes 4 stone ALA4 GL and a rubber Membrane Coactive airstation.All have the same hose length and are in 12 ft of water. A lot of visitors here tell me that their diffuser boils the water. I tell them that the round stone is turning 500-600 GPM and switch to the Great lakes @ 1250 GPM and lastly the Co Active which is turning 2778 GPM and can you tell me which is which.This set up is 50-60 ft off shore and the boil "looks" the same on each one.(no one has got it right yet) My point to this display is that a boil is often a real fooler on knowing if your turnover is what you want and need it to be.I test many ponds with a good boiling diffuser but with low DO and 9 times out of 10 the diffuser is the problem not the pump. In your case with small impoundments your odds are greater that you are getting a good turnover as you can confirm with your DO meter.Aerate properly and forget the DO meter for the average pond owner and $600.00 saved, Cecil your ponds are not average however. Ted