Pond Boss Forums AERATION Should I aerate? Aerate 24/7?

I am new here so be kind. My pond is about 3 years old and I never have heard of this start-up sequence
that everyone talks about. I just go to my aerator when the water warms around 65 in the spring and turn it on and never turn it off until the winter.I guess I am lucky I haven't killed all of my fish yet. My question is should I aerate 24/7 or should I focus on nighttime aeration? I live in Texas and it is really hot day and night.If I leave my aerator off during the scorching hot day I tend to get pond scum forming pretty fast.I also am in the process of clearing my .33acre pond with Alum and was wondering if I should leave my aerator on during and after my application of Alum?

Hey DBW,
I'm pretty new here too and also live where its hot. I just started aeration and plan on 24/7 b/c of heat. I have read alot on here about it and there are some who do it 24/7 and some use the nighttime early morning routine. I'm sure there are some other factors involved besides heat.

There are some aeration specialist on here they'll have some good advice.

HI GUYS,
MY POND IS IN THE NORTH SO MAYBE THIS WON'T MEAN ANYTHING FOR YOU GUYS BUT I RUN MINE ALL YEAR. IN THE WINTER I MOVE THE STONE TO A DEPTH AROUND ONLY 3 FT . IN THE SUMMER I RUN IT ONLY IN THE EVENING AND NIGHT. SOME OF THE OTHER GUYS ON THIS SITE HAVE PONDS IN TEXAS AND WOULD BE MORE KNOWLEDGABLE THAN MYSELF ON THIS.
I AM SURE THIS SITE WILL HELP YOU BOTH A GREAT DEAL AS IT HAS HELPED ME.

dbw1968-

You are lucky that you have not killed fish. Your pond must be fairly young and the build up of hydrogen sulfide and carbon dioxide is not too great.

For the future, start your system for 15min the first day, then turn it off. 30min the next day, 1 hour the next, 2 hours, 3 hours and continue to add an hour until you reach 6 hours of continuous use. This will reduce the possibility of a fish kill due to the introduction of toxic gasses.

What type of system do you have? In a .33 acre lake, a single diffuser system depending on the type of diffuser and the depth it is placed should be more than sufficient.

With increased algae blooms if the system is off, that is a good indicator that the nutrients like phosphates and nitrates are still free floating in the water column and most likely being released from the bottom sediments. You mention that that happens only with the system off during the hot days.

With the system on you are meeting the oxygen demand and changing the bottom chemsitry so those phosphates and nitrates are locked up into the bottom sediments. This also allows the pond to assymilate any extra nutrients that are washing in during storm events.

Your question about 24/7 operation. I think if you want to keep the algae at bay and make sure you do not build up a layer of hydrogen sulfide gases, the only option is to leave the system on 24/7 during summer. The only true way to measure the requirements for a pond's oxygen demand is to have an O2 meter. This will alow you to find not only the oxygen levels at depths but the temperature as well.

Bass Pro had some on sale recently for $100 with a 15' marked cable and probe. I picked one up for a secondary back up meter to my Hydrolab.

Alum treatments: Buffered alum? While doing the treatment, I would turn the system off. You want the alum to bond with particles in the lake and sink to the bottom. This happens quite quickly 1-2 days max. Then I would turn on the system. Observe it to make sure you are not re-suspending the particles. If so, turn it off and rais the diffuser above the slurry level created by the sinking alumn.

I hope this helps you answer some of your questions. If you have any more, please do not hesitate to post. It takes us some time to get back to the page during summer with all of us in the field working.

Every aerator should be sold with an O2 meter. If you figure 7 cents a kilowatt-hour, a one horse aerator running day and night will cost in the neighborhood of $50/month to operate. Not every pond is going to be a hypereutrophic hatchery raceway posing as a real pond, so some pond owners would be wasting money by aerating during clear weather. It's not worth second guessing your O2 levels at depth. Just get a very basic O2 meter and aerate accordingly.

Just wondering if anyone could tell me what the ideal DO levels are for a pond? I bought a YSI55 DO meter and have been taking some readings at my pond, but I'm not sure what the acceptable levels are.

EDIT:

Actually, just to clarify since different types of fishes need different DO levels, what are the acceptable ranges for some of the most common pond fish?

This forum sure brought back memories! I remember when I got my aerator and put it in my pond for the first time. There were no fish in it yet, and it really smelled bad, like rotten eggs. I put it clear down to the bottom, 17 feet deep. Now it runs 24/7. I don't want to go through that again now that it has fish in it. The way things are going, to save money I might shut it down next winter. I dont have that many fish in it.

When DO is below 4 mg/L(ppm) most warm water fish are getting stressed. Numerous warm water fish can tolerate 2-4 mg/L for short periods then piping or gasping at surface begins, thus showing their stressed condition. DO can get high in the 14-16 mg/L range and still be okay for fish. Higher DO levels can at times start to cause some problems. IMO acceptable or preferred DO concentrations are in the range of 5 - 14 mg/L. Coldwater fish do best in above 5-6 mg/L. Fish spawning and egg development is best when DO is above 5-6 mg?/L.

Interesting note is that rainbow trout do okay at 5mg/L when stocked into Lake Titicaca where because of altitude the DO concentration in fully saturated water is never over 5mg/L.

Bill,

Thanks for the info. I checked my DO level again this evening (at 6 pm, water temp 59*F, and at 1' below the surface) and was getting readings in the 7.76-7.90 mg/L range. The pond is only about 2-3 years old, and I'm concerned that the readings are too low, for this time of year. I do not have an aerator set up (I plan to, as soon as I get electric to the property), but the pond receives a very good amount of wind.

Also, I have a question about calibrating the meter. I've followed the directions and have replaced the membrane and solution and have entered the correct altitude (660'), but when I place the probe in the moistened storage well, I get a reading of 7.1 mg/L (68*F) which is 77.6% saturation. Shouldn't this be 100% saturation?

Your reading should be 100% saturation in the moist storage chamber, Be sure you do not have an air pockect under the membrane. 59F water at sea level would show 100% stauration at a reading of 10.1,// 72F would be 8.7 and 86F would be 7.5 If you maintain 70% plus saturation in water above 70F you should be fine in your "neck of the woods"Your readings without aeration will flucuate more on a daily basis than with aeration.

Thanks, Ted, that is what I thought (concerning the 100% saturation). The interesting thing is that when I enter my elevation as 0 (sea level) I get 100% saturation in the storage chamber, but when I enter my correct elevation, the reading goes down to about 78%. I double checked the probe and there are no air bubbles beneath the membrane. I bought the meter used, do you think it may need serviced? or, can I use "sea level" as my elevation and assume I am going to get the correct reading?

Yes , I would use sea level/ also consider calling Aquatic Eco Systems @ 407-886-3939 as they are a service center for YSI and float your situation past them.It may be something very minor and good luck.

I just tried calling Aquatic Eco Systems, unfortunately, they were already closed for the weekend, so I will try next week. Also, I took another reading at the pond today with the meter's altitude/elevation set to 0 (sea level) and was getting 10.1-10.2 mg/L at 60*F.

10.1 would be 100% @60F, If that reading is in the top ft it may be accurate, If it were taken with a lot of sun it may be accurate,Try testing in top ft and slowly lower to approx 1 ft off of the bottom, the DO reading should get lower with depth in your situation.If the temp does not change when you lower it you are not getting an accurate reading.

The reading was taken at 11 am, the sky was overcast and there was about a 20-25 mph wind from the south. The measurement was 1 foot below the water surface. So far, I have been only taking the measurments as far out as I can reach from the shore, which is only a couple of feet deep. Next time, I will try attaching the probe to some sort of float so I can reach deeper water.

Be carful about sending your meter to AES. I don't want to bad mouth them but I sent mine in for regular maintainace and got a bill for way over $200.00. They said the probe needed to be replaced but I question that. The problem was I could not get my meter back until I paid the bill. I think I'll try YSI itself next time.