Pond Boss Forums AERATION Systems questions New system install

Well here goes nothing........

I have a pretty fresh pond that was finished in early march. The deep end of the pond is about 10' - 12' currently and the other half is in the 3'-5' range. The pond is about 5/8 of an acre (100' x 250'). I have put togeather my own system and just want to get some thoughts before install on Saturday. I have bought a Thomas linear pump that is rated at 4.5 CFM and will be running air through approx. 250' of 3/8" ID tubing to the deeper end of the pond. My guess is I will see about 3.5 CFM at the stone in about 10' of water does that seem about right? That being the case will that be to much air for a pond of my size? I have installed a ball valve on the outlet side of the pump so I can cut down on the air a bit if needed. The pond was stocked in late March with about 30-LMB, 200-HBG, 30-CC and about 15 - 16" rainbows along with 30 lbs of FHM. The pond is on my vacation property so I am going to put the pump on a dust to dawn timer to run at night. Will this be introducing to much air to fast? If so I can adjust timer to only run 2,4 or six hours at dusk for a couple weeks. The main problem is after this weekend I will not be able to get back to the property for 2 weeks. Thnaks again all!!!

Welcome to the forum, BIGBRANDO (is there any other kind?)

I am assuming the pond is full now.

I am not qualified to comment on the sizing of your aeration system wrt your pond. However, a new pond, newly stocked 1) should not have a bottom full of "bad water" that you need to be really careful about while starting up an aerator, and 2) should not have a huge need for 24/7 aeration, especially fairly early in the year in MI. So if you don't get better info from any of the myriad of sources more capable of providing it, I'd go Middle-of-the-Road at startup - maybe 6 hours a night for those first two weeks.

Welcome to the forum as well, BIGBRANDO

What is the model number of the compressor? Unless, you already have the pump curves that we can use to figure out the cfm at depth.

To reach a 12' depth, the compressor will need to produce at least 5.33 psi again just to reach the depth. In 3/8" line, pushing 250', the friction loss will need to be added to that 5.33 psi to achieve what the total psi will be. Then you can take that number and see what the cfm will be on the pump curve at the total psi needed.

What is the type and requirements of the diffuser you will be placing in this pond? Do you have the turnover rates at the depth of 12 feet for this unit?

By calculating the total volume of your pond and knowing what the circulation rate is of the diffuser, you should be able to calculate if you will be over aerating or worse underaerating. Unless you are trying to keep a plankton algae bloom, overaerating will not hurt the pond since really we are ciruclating with the bubbles and not injecting pure oxygen into the water.

As Theo stated, with this pond be basically Mesotrophic (NEW) the oxygen demand is low. I would not worry about the start up and introducting a large amount of "bad water" since it probably does not exist. The only way to know for sure is to use a oxygen meter.

If you have any more questions, I'm sure one of us will be here to help you.

Thanks all!

The compressor is a Thomas #5120s spec sheet attached

http://www.gd-thomas.com/WorkAreashowcontent.aspx?id=20390

I found the curve, currently the guage is showing about 10psi with no load so I am guessing about a 6.5 psi loss which should leave me around 4.25 cfm. From the little bit of research I have done that seems like a little much. As long as over aeration will not hurt anything I think I should be in good shape. What should I do in the winter months when the water freezes? Maybe only aerate a couple hours? I have read a little bit about over cooling and defently want to stay away from that as well. I am using a 9" round sone as my diffuser.

Yes, you can cut way back (or off) on aeration in the Winter. You may not need any, unless the ice gets covered with snow preventing light from entering the water. If you have to guess on the weather ahead of time due to absence, that 2 hours would probably do it. You can see this Winter how much ice thickness 2 hours a day will clear and have a better idea.

wonderful thanks!! I am just a bit paranoid because a friend of mine in the same general area has a 3 year old pond and lost everything to winter kill and my thoughts were because of no air. What else could cause this? We had a fair amount of snow in Michigan this winter so I am pretty sure the ice was snow covered for most of the winter, which will be the case with my pond as well. I am lucky to make it up to my place once a month in the winter, that being the case I would want to keep the aerator running just a couple hours a day all winter?

Snow covered ice is probably the foremost cause up Winterkill.

I'd figure on 2 hours per day next Winter for starters, then see how it looks on your visits.

For additional aeration answers and questions (including "Supercooling"), see the archive thread Aeration Simplified.