We had a quote for a system speced out for our pond. It was nearly $7,000. That was way over our budget.

Question: Is it advisable to put in a smaller unit in order to provide at least some aeration? Or is that pointless? Are there units we can build on over time?

Backstory: We have serious suspended algae issues and a worsening FA issue. We had the water tested and have an extremely high phosphorous level. The biologists who visited the pond thought the high nutrient levels were a result of the leaf litter on the pond bottom. The pond is 40 years old and surrounded by trees along much of the banks.

Sounds just like my pond!

Hartfish how big is this pond? How deep? 7 grand seems a bit high but once again not sure how big your pond is? That would make a big difference depending on what you need for air.... Do you have a pic or 2? Others here can help you out for sure but they will need a little more info...


RC

I'll offer some thoughts about this question until our aeration experts chime in.

I am of the opinion that an undersized unit is of little benefit. I looked at a nice-sized lake that has a seriously undersized unit on it. We checked oxygen levels and found that the lake was still stratified and, even though we could smell some gasses being released via the bubble plume, most of the lake was unaffected. About two weeks later the lake turned over and acted as though it had no aeration at all. That landowner was lucky that he didn't lose any fish.

Hart what you need to find out for sure is if the quote you got above is for a system that fits your pond. Maybe they quoted you for a system waaaay to big.... and what you think may be undersized is not undersized.

Of course Bob is correct in saying you don't want something that won't do the job either, but if you give the pros here a little more info on your pond maybe they can help you the right direction as far as what you really do or don't need....


RC

Hart, I'm right along with you and RC51 in that my pond is surrounded by trees with my pond being 40-50 years old with a LOT of muck at the bottom (when I started 2 1/2 years ago).

My pond is kidney bean shaped, 2 acres and shallow (4-5' average except for 9' depth along the dam).

June of 2012 I installed 4 double Vertex diffusers (3 shallow, 1 deep), 3/4 hp compressor and 700' of weighted tubing. All for under $3k.

I installed it myself, building the cabinet to house the compressor and manifold.

As RC51 said, give the experts here a really good idea of what you have to work with such as dimensions, depths, shape of pond, photos, etc., then read up and read up some more!

It's AMAZING what you can learn here!

Hart, as Bob said, undersized aeration isn't worth the effort from an economic to benefit standpoint.

My first thought on the biologist's theory for high P is...since the leaf litter is in anaerobic (oxygen starved) water, it is decaying 1000's of times slower than it will once proper aeration creates an aerobic (highly oxygenated) environment. If the high P is due to now slowly decaying leaf litter releasing the nutrient, then aeration will release MUCH more, MUCH faster. I am also hope that $7K quote was for a well built compressor housing and installation. Companies have to make a profit to survive, so if they quoted you a larger, top quality Vertex system, weighted tubing, electrical wiring, quality compressor, enclosure and various parts needed, $7k is not unreasonable at all.

You could get other quotes on aeration systems, but a properly sized unit will almost always be well worth busting a budget! Since you have high P, in addition to aeration, you could treat your water with Alum, which will bind the P and render it unavailable to the algae.

How large is your pond? General shape? Coves? Average depth? Any "holes" or islands in the pool area for structure and topographical changes?

Thanks for the input.

The pond is 3.5 acres with a max depth of 22 feet and an average depth of 8 feet (that's a guess, but it appears to be a fairly deep pond all around.) It's generally an elongated triangle with a small island at the narrow end and a small cove around the middle.

I went through one of the aeration companies that does a quote based on aerial mapping and data that I provided through their web site. I believe it was Airmax.

The system that was quoted was for everything except installation.

Wow!! 7K without installation gotta be crazy!! As the old song goes my friend.

"You Better Shop Around" IMO that's way to high. With out seeing this pond if you say it's pretty much triangle I would say you need 3 stations. 3, 9 inch fusers on each station.

Your weighted hose and your pump or pumps are going to be your biggest cost.

Do you have electrcity near by? If so that's half the battle.

Even vertex fusers are not that expensive. I think there like 30 or 40 dollars a piece. So lets do some math.

Lets see.

You need 9 vertex fusers at let say $45 bucks and that may be high. That's $405 dollars

You may be able to get 1 pump to run the farther air station and 1 pump to run the 2 other stations and use a gang valve to equal out air to both of them. Pumps can be costly.

So let say you bought 2 pumps lets go big and say they are 3/4 horse considering I have only a 1/3 horse on my 1 acre pond 2 / 3/4 horse pumps should be more than enough for you. Remember this is just a basic guess here of course you can get specs on your pumps to fit them better to your needs. But with 2 of your 3 stations being in 8 feet of water or so 3/4 should be over kill / plenty! So let say 2 pumps. I never seen a 3/4 brand new over 1000 dollars? But lets just say they were a grand a piece! Thats $2000.00 dollars for pumps. Now you need weighted hose 5/8ths inch ID is good. This stuff is not cheep either.

I bought 75 feet from Ted Lea(God rest his soul) for like 120 bucks. So lets figure high once again! So lets say you need 800 feet of hose.

2 stations get 200 feet and the 3rd station gets 400 feet cause it's farther out there in the pond.

If you do the math with what I paid from Ted. Take 800 / 75 that = 10 then take that times 120 bucks you get $1200.00 dollars for your hose.

The only other thing you need is a little bit of PVC to connect up your fusers and to the main air lines and a weighted down plastic milk crate to put them on. So let say all of that coset 300 bucks. What do we have.

Fuser cost $405 dollars
Pumps cost $2000 dollars
Hose cost $1200 dollars
Misc cost $300 dollars.

Total = $3905.00 for one heck of s system!! Keep in mind these numbers are retail give or take. And they want to charge you 7K and NOT installed NO WAY man like I said they must think you have money to burn! Wow!

Sorry this just upsets me it's like seeing a girl going to see a car mechanic they see them coming from a mile away!

RC

Side note to this. If they are figuring you are gonna need 4 or 5 stations price of course will vary some but still not 7K before install.......

Hi Hartfish ~
7k for a 3.5 acre pond does sound a little on the high side. I would recommend a second opinion....
Under-aeration in my opinion and experience is worse than no aeration. When you under aerate you mix the water without getting the oxygen levels where they need to be, so you are basically mixing the bad water with the good water and making it all bad.
In your situation, though, I think you may have been quoted more than you need.

Hart get a quote from someone like Sue or someone else on this site that you can trust. I am not 100 percent positive but I would be willing to bet a 100 dollar bill they can do better than that quote!!

RC