Pond Boss Forums AERATION Systems questions Please help me design my aeration system

My thoughts exactly, esshup.

Thanks very much for the detailed response! Do you mind some questions based upon it?

1) Don't you think the water jet I plan to install under the dock, aiming across the beach planned for the pond's northeastern shore, would alleviate the need for a summer diffuser in that lobe of the pond? That would get me down to two roiling water spots instead of three, anyway. (Viewing and swimming aesthetics and my wife's view of them, remember...)

No. Bottom aeration diffusers bring water up to the surface so it can absorb O2 from the air. The water jet will move water horizontally, and might help keep the muck from settling onto the swimming area bottom, but that all depends on how powerful of a motor you use.

2) Working on that same issue a bit, what would be the downside of using only one instead of two summer diffusers? Is it just that I wouldn't be aerating as much of the pond's area as is ideal, i.e. there would be some spot(s) where the substrate and water remain more or less as they are now (stratified in temperature and oxygen level, laying down muck)? That might be a trade-off I'd consider accepting, say, by putting a single diffuser in the pond's deepest hole as far out from its southern shore as I can while staying at the depth, leaving out a second one for its southeastern lobe (which I suspect is the obvious spot for a second one).

Under aerating can cause more of an algae problem than not aerating at all by bringing up a constant stream of nutrient rich water for the algae to feed on. So, it's either all or nothing. As to the "boil" that she dislikes, can you find a picture of it and post it? I'm wondering if she saw a aeration system that wasn't set up properly, or if she saw a surface agitator and thinks that is a bottom diffuser.

3) While we're at it, what's the reasoning for wanting to turn the water over at least once, preferably twice, every 24 hours? I know that it's a commonly accepted goal, but my education is lacking on why. I am a biologist, though, so don't be afraid to get technical on me if you're so inclined. :^/

Refer to the answer to question 2. For more technical data, the low DO water absorbs O2 from the atmosphere. By bringing up that volume of water, it is exposed to the atmosphere. You want to have a minimum of 5 mg/l O2 levels down to the pond bottom to ensure that there is enough O2 for the aerobic bacteria to stay alive and flourish, more O2 is better. Bring up less than that and you might not reach those DO levels.

4) What do you think of the idea of my placing one of the two winter diffusers close to shore by the pond's northwest "corner" (the sharp little point in the shoreline) and another one close to shore on the south side of the peninsula almost directly across the pond from that first spot, in the pond's southeastern lobe? Those are both spots where aquatic vegetation (a native pondweed in both cases, but I forget at the moment which species) other than Chara at least has a toehold, and I thought it would be good to encourage its growth.

It really doesn't matter where in the pond the winter diffusers are, as long as anything that accidentally falls into the water can get out without having to climb up on the ice. I almost lost 2 of my English Springer Spaniels because they got too cold chasing after a few geese that they could not climb up on the ice to get out of the pond. I barely got the ice broken to shore so they could swim close enough for me to grab them and get them out of the water. It took 20 minutes in a warm/hot shower for them to stop shivering. Plants don't actively grow during winter. If you are not concerned about a possible fish winterkill, then you don't have to aerate during the winter at all.

5) You're obviously a Vertex fan, and I appreciate manufacturer/model recommendations as much as any other kind (so doubly thanks!). Can you tell me what you particularly like about their equipment, or dislike about what you see as their nearest competitors' equipment?

The only thing that I will say is that Vertex has testing data to back up their advertising claims, and that data is used to properly design an aeration system for a particular pond. AND they publish that data for the general public to view it. If you know of other manufacturers that publish their design data, please post links to the data.

6) How deeply buried do you think the 1" poly should be running from the barn down to the pond's edge? It's very rocky around these parts - I'm told the pond was created using dynamite leftover from blasting out space for the house's foundation - so I may be in trouble if it has to be very deep. Winter temperature-wise I'm in USDA plant zone 5a (-20F to -15F), if that's important to the answer.

Just deep enough so that you won't cut/hit it while doing any other digging. If 6" will do that, then that is deep enough. But, plan ahead. If you only go down a few inches, and 10 years down the road you want to rototill the area that has the buried air line in it, be prepared to do some repairs.....

That's all I have for now, anyway. (Sorry about it being so much! :^/ ) I want to pick your and other folks' brains about aquatic plants to establish in the pond, too, but I'd rather leave that for another thread at another time.

Thanks again - and a lot!

Gerry