DIY Pond Aeration – How To Build The Best Pond Aerator

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Written By Mark Washburn

Mark has 20 years of experience as a professional pond management consultant.

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In this video I want to cover some tips for you if you’re looking to do something in a DIY form of pond aeration. The topic of DIY is very popular these days and I’m all for it because it helps people save money particularly those on a budget that are trying to keep the cost down of investing in their pond a bit, but they want the advantages that aeration can give them.

So you know, despite the fact that I have worked in commercial aeration for many years I understand the need for for that kind of flexibility, so hopefully some tips here will help you as you go through your research and as you design a system for your pond.

The Main Components Of Any Pond Aeration System

Lets let’s start with the basics…so we’ve got three components in a typical aeration system. You’ve got the land-based pump, you’ve got some form of air line which is feeding that air from the pump, down to a diffuser that sits at the bottom of the pond. That is sub-surface diffused aeration, and it is in my opinion, the preferred way to aerate a pond for a variety of reasons. From economic and budgetary reasons and cost of operation to the actual effects that you get in the pond and ease of maintenance, it just makes good sense to consider it.

I also want to address a very basic premise that I have, and that is when somebody says well any aeration is better than no aeration at all, I agree with that, although I think there are different levels of variation, different levels of quality and effect and and all that, but I do think that almost anyone can benefit from increasing the circulation and the turnover in their pond and increasing oxygen in various ways.

Part of what I’m going to discuss today is about optimizing that to the best of your abilities so we’ll get into that a bit later on when we talk about diffusers.

Choosing The Right Pond Aeration Compressor

Let’s start with the pump though. A land-based pump is what you will typically see used in the DIY realm of pond aeration, and of these, linear compressors are common. These are septic tank type compressors or pumps that are using diaphragms to create the air They tend to be very quiet, and tend to be extremely economical to run, usually costing just a few bucks a month, and they can put out quite a bit of air. They have one limitation though that may affect your decision and that is depth capability. Be sure whatever pump you’re looking at getting or thinking about getting, make sure that you contact the manufacturer or the distributor or retailer and find out what the depth rating is on that pump because typically most of these linear pumps will work down to about eight feet. Some may go a few more feet but there are others that may not do well beyond six feet and so you definitely want to cover your bases there. You’ve got to go out and determine how deep your pond actually is.

If you are eight feet or less, a linear pump of some type should do the trick. If it’s beyond eight feet or deeper than eight feet you most likely will have to look at something like a rocking piston compressor instead of a linear and they are workhorses for us in in the commercial realm and they’re relatively affordable. The are also efficient but not quite as much as the linears but they handle depths from six feet all the way to almost 50 feet and so they’re very very versatile pumps and it’s just something you’re going to have to consider if your depth is is greater than eight feet.

Protective Aeration Cabinets

Weather protection for the pump needs to be a consideration too.
Not all of the pumps are weatherproof, in other words some of the linear designs that you see will have a weatherproof casing on them or cover on them so you don’t need to do anything else, but there are some linears that are not weatherproof and the majority, if not all of the rocking piston pumps are not weatherproof at all they’re just the bare pumps. So they need protection from the elements. They cannot get wet, and the other thing specific to the rocking piston pump is that in its operation it’s meant to run 24-7…they’re great continuous duty pumps, but they get very hot. You would not want to touch the top of the piston cap after it’s been running a while and so if you’re going to build your own cover, which many people do, again to save on cost…you’ve got to get that heat away from the pump.

All factory cabinets that we sell have cooling fans in them so I would look for a cooling fan or inexpensive exhaust fan if you build your own cabinet. Make sure it’s well ventilated and make sure that it keeps the pump dry and get a fan that’s pulling the heat out of that box. If you don’t…when people have misjudged that element…they have melted parts off pumps and so definitely with rocking pistons you got to keep them cool. Ideally you want to keep them pretty clean too so try to pick an area where the pump’s not in a bunch of filth and dust and you’ll get better life out of whatever you’re using.

Weighted Airline And Burial Tubing

As we move on down the line lets talk about the airline. One cost saving area is to look at polyline as it’s an unweighted inexpensive airline. Usually 3/8” is typical and that would run from the pump to the diffuser in the pond. I have a problem with the poly however.

First, it’s not weighted…so you have to add weight to get it to sink and stay down on the bottom of the pond. This, to me, is a pain to do.

Second, it’s not very stout…it usually doesn’t kink but could, and I don’t think the durability holds up as well as the weighted line does. Usually for these DIY packages you aren’t talking about a lot of airline…maybe a few hundred feet at the most…and so for the cost difference, and the benefit I get out of the weighted line, I just think it makes better sense to go with that option. Still if money is really tight, poly airline will certainly get the air to the diffuser which is the most important thing.

The other common use for poly line, is to use it as burial tubing.  It’s more cost effective when putting it in-ground and burying it about 8 inches down in most locations.  Some companies suggest using PVC, which is much more stout and durable, but poly line can work alright too.

Pond Aeration Diffusers And Diffusion

As we move into the diffusers, which go into the pond, there are typically three types you’ll see. The stick diffuser form which is just a stick with a rubber sleeve over it that has a membrane pin holes in it and the air comes out of those holes. You’ve got plated diffusers where the rubber membrane is on top of an oval and the bubbles come out the top of that and then you also have rings, different forms of rings that would have a diffusion tube, that creates the little air bubbles needed for diffusion.

In all the commercial diffusers, no matter the form, tend to have very very fine small holes in them. There’s a big difference when you talk about the diffusion of of the air, I see some people suggesting that you can take a p pipe or PVC and you can drill small holes in it one to create a diffuser. You’re never going to get holes as small as the membranes with a drill. Will larger holes still move some water? Yes, for sure, but it won’t compete with better diffusion.

It’s important to understand the difference between coarse bubble diffusion and fine bubble diffusion. So if you’re looking at a PVC pipe with holes in it, that would be a coarse bubble diffuser design. They are good at creating mixing in the pond. In other words you are able to circulate the water enough to turn it over and provide more of a balance between the top and the bottom of the pond. The temperature gradients will go away and you may get a little bit of oxygen from above to circulate down below. But mixing is not all that we are after in most ponds.

Fine bubble diffusion actually provides much better oxygenation, and that’s a big thing to think about. Tt does provide mixing and while it’s not as powerful as the coarse diffusion, it’s a very well balanced mixing more that’s more gradual or subtle. Coupled with the increase in oxygenation, your dissolved oxygen goes up quite a bit because of the reaction of the fine bubbles at the surface. Finally there’s an economical benefit to the fine bubble diffusion. Fine bubble diffusion creates a much greater benefit to the pond overall, with less air input. In other words you get a nice balance of all these things without having to go to a higher horsepower pump, whereas the course bubble diffusion handles higher air volume…and you may need it to turn the pond over. Beyond that, you’re just spending extra money to get a moderate benefit in the pond.

There are places like wastewater where coarse bubble diffusion actually is probably better but in most ponds that have fish, where you’re trying to improve its condition, and most of what we want as pond owners, will be more realized I think by using fine bubble diffusion.

To get that you’ve got to go with something commercial. Of what’s on the market, these diffuser sticks are actually not very expensive and they can be hooked up in various ways to the airline. I would try to elevate them or get them off the bottom as it helps keep them cleaner and helps debris from getting in them and messing things up. Every commercial diffuser we work with has an element of elevation where the diffusion release point is actually well above the pond bottom and so I would put a a stick or an oval diffuser on a milk crate or something to keep it elevated. This is a relatively fairly cheap and easy way to go.

Finally I would stay away from air stones. Over the years I’ve found that not only can they break pretty easily, but they tend to clog up faster or more fully (and be harder to clean) than the membrane diffusers. Will they work? You bet, but I don’t think they are the best way to go for air diffusion.

So that’s about it. If you do a bit of homework…checking your pond for the actual depths, and making sure you get a pump that can handle the job at hand, and pick a good diffuser to go with it, there’s no reason that your DIY pond aerator won’t give you years of good service, while it helps your pond look better, and keeps your fish happy too. In the end, that’s the most important things of all.

If you have questions about pond aeration, be sure to reach out to us at AmericanAeration.com. We’ll do our best to help.

See below for products mentioned in this video.

Some Suggested Components

Linear Pumps – Here’s a good one if your pond is 8′ deep or less. –  https://amzn.to/3t1XUSI

Rocking Piston Pump – The 1/4 HP will power up to 2 diffusers – https://www.klmponds.com/kaskm60​

Weighted Airline – 3/8″ 100′ rolls are commonly used. – https://www.klmponds.com/airline

Diffusers – Here are several affordable options for diffusion.

6″ Stick Diffusers – https://amzn.to/2Qa63pD

Ring Diffuser – https://amzn.to/2Qa63pD

Multi-Stick Diffuser – https://amzn.to/3uB5CU9

 

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