trying to understand why ....

[gardengimp]

one would turn off a water garden submersible pump from noon to six that is a mechanical filter as well as a pond aerator by way of an umbrella fountain.

Florida penisula, summer time, typical late afternoon thunderstorms and/or cloud coverage. Hot, hot, hot. This is the only aeration in the pond. Small pond, a whole lot of lilies and algae. Lots of gambusia and tadpoles, one large goldfish. Water is not green, nor does it smell.

I've been reading and reading some more, trying to understand the logic behind turning the pump off during the afternoon. I'm coming up blank and hoping you all can sit me down and get me some learnin'. Thanks ....

 

[Waterbug]

I don't know what you've been reading so I'll just cover a few basics.

Most people would say to leave the pump running 24/7. Nothing wrong with that. Fish are always going to do better the better with good O2 levels. It's the same as you being at sea level vs 18,000 ft. You can live a long time at 18,000 ft but you're not going to be very active and you'll lose weight as you're not able to digest food as well. Fish have the exact same issues.

Many ponds don't need any pump to keep it aerated enough to keep some number of fish alive. I know this sounds unbelievable to many people but fish have lived in ponds long before there were even humans. Then there are also ponds with high fish loads where all the fish would die quickly should the pumps stop for even a short time. Fish can die even if the pumps don't stop if they aren't providing enough water movement. Most pond keepers don't have the test equipment to know whether their pond has enough O2 and just have to hope for the best.

If you did want to turn off a pump then afternoon would be a pretty good choice. All that algae produces O2 and consumes CO2 when the sun is out. At night the algae consumes O2 and produces CO2 so running a pump then you get max benefit.

And now for the thing you will probably never believe...virtually no one in pond forums does...your umbrella fountain...not really doing a lot aeration wise. Same with streams and waterfalls. If you took off the fountain attachment you would get more movement inside the pond and increased aeration. The pump will move more water when head is reduced to zero.

Gas exchange happens at the surface and a fountain does increase surface area. But the gas exchange happens very fast. If you could see gas exchange you would see it in the fountain just around the nozzle, the rest of the water is fully aerated. In a say 1' stream the water would be fully aerated, increasing the stream to 100' wouldn't increase aeration, it was already fully aerated in the first 1'. A lot of the pump's energy isn't converted into aeration. If instead the pump was moving more water from the pond bottom to the surface you would get more gas exchange.

If you're looking to save some money on electric you could add an air pump. Most people think it's the bubbles, but it's water movement again that provides most of the aeration. Air pumps are just more efficient at moving water at low head.

 

[shanezam203]

good read, thank you water bug.

 

[sissy]

I have been looking at the air max aerator and as wondering if that would be good for my pond

It seems to have low energy cost and comes as a whole kit and the replacement bladder is easy to change out and cheap also .They have bigger kits and a video on you tube.I was looking at the 4 port one

 

[adavisus]

Well balanced fishponds won't usually run into aeration problems with no water squelching devices, but just before dawn you may find fish driven to the surface to gasp for air, a time when they are vulnerable to Mr. Heron...

Regards, andy
http://www.flickr.com/photos/21940871@N06/
http://swglist.wordpress.com/

 

[gardengimp]

Yes, I thank you also wb. I am still getting my head around everything you wrote And going back and reading this ifas pub http://edis.ifas.ufl.edu/fa002

I am still trying to understand why summertime + fish = turn pump off in afternoon. Whereas summertime no fish == pump runs all day. Part of my struggle is the typical Florida late overcast afternoon. I think that shuts down photosynthesis ?

And gas exchange, how much of the bottom top turn over is effective in 18" or so deep water?

Anecdotal - I have a half barrel still water garden in full sun. Half buried. No electric. Two two year old comets call it home.

Thanks again.

 

[sissy]

I really don't think anything is set in stone when it comes to ponds .I took a pond out for a realtor abandoned over 3 years or more ago .Talk about stink and plant choked but there were 6 healthy over 2 foot long koi in the pond and it was not a big pond 15x 15 at least thats what it looked like .and around 3 feet deep .No electric in the house for over 4 years and they looked great and gave them away to a newer pond owner and the fish still look good and healthy a year later and thats the only fish the people have and gosh are those fish friendly . .I was amazed anything could live in that muck and stench .Not sure how the fish even moved around .Sometimes I think if you fuss to much you will loose fish .Step back and watch and it seems to always work out .

 

[Waterbug]

I am still trying to understand why summertime + fish = turn pump off in afternoon. Whereas summertime no fish == pump runs all day.

I don't know where you're reading this??? I didn't see this in the link you posted. Maybe you can copy & paste the specific section you think says this? I don't know the context. For example an article on how to grow algae, which is a serious business, would have no fish and would run pumps all day, as they're trying to maximize algae growth.

The article you gave a link to was mainly talking about fish rearing ponds, huge ponds. In these ponds the cost of energy needed to move water is too much to run pumps 24/7 and still be able to make money on the fish. For these ponds pumps are only used to try and get fish by the deadliest O2 levels and no more. As the article says, they test water almost 24/7 to determine whether pumps need to be turned on.

Part of my struggle is the typical Florida late overcast afternoon. I think that shuts down photosynthesis ?

Slows down, not shutdown. But if your pond is relying on algae O2 production to keep fish alive I'd guess you will awake to dead fish at some point. Fish rearing owners track O2 levels closely to manage the issue. Without that they would lose many crops.

And gas exchange, how much of the bottom top turn over is effective in 18" or so deep water?

I'm not sure what you mean by "bottom top turn over". I can tell you in still water gas exchange happens only in the top 1/16" or so, I don't remember exactly, but very thin. Then gas exchange goes down fast beyond that top layer. That's why the article talked about wind being important as it mixes the water a little and can greatly increase gas exchange, but it still isn't much compared to a backyard pond with a pump. But then backyard ponds generally have much higher fish loads compared to these fish rearing ponds.

Any water movement you can provide will be "effective" from some standpoint. Whether a certain amount of movement is effective in keeping your fish alive totally depends on your exact pond and conditions on that exact day. Your neighbor could have the same size pond, same number and size of fish, same pump, and your fish might all die while theirs make it through because maybe yours has a little more decomposing waste or you fed your fish the night before and they didn't. The difference between fish living and dying is a very thin line.

 

[gardengimp]

I am still trying to understand why summertime + fish = turn pump off in afternoon. Whereas summertime no fish == pump runs all day. Part of my struggle is the typical Florida late overcast afternoon. I think that shuts down photosynthesis ?

I don't know where you're reading this??? I didn't see this in the link you posted. Maybe you can copy & paste the specific section you think says this? I don't know the context. For example an article on how to grow algae, which is a serious business, would have no fish and would run pumps all day, as they're trying to maximize algae growth.

The article you gave a link to was mainly talking about fish rearing ponds, huge ponds. In these ponds the cost of energy needed to move water is too much to run pumps 24/7 and still be able to make money on the fish. For these ponds pumps are only used to try and get fish by the deadliest O2 levels and no more. As the article says, they test water almost 24/7 to determine whether pumps need to be turned on.

Where am I reading this? It is one of those everybody knows things that was said to me. Sort of like 'Everybody knows you should not lean over the pond when you feed the fish'. So I am a noob and not an everybody, so off I go to learn why. Actually, I like the reading and researching part ... provided I can find an answer. So somebody says to me, 'since there is a goldfish in that pond the pump must be turned off in the afternoons during the summer'. I'm trying to understand the why's that statement would be made. The IFAS document I linked has come the closest to addressing the florida afternoon summer conditions that I **think** must be the root of the everybody knows statement. But, I don't really get it yet.

And WB, I have to thank you for all the time you spend explaining these things in such easy to understand ways and means. I know it takes time, but speaking for myself (and guessing for a bunch others) we all appreciate what you do.

 

[Mmathis]

Oh, I think I get it now! I was also having trouble figuring out just what you were talking about, GG. I think the confusion was in the way you presented the question/thought. Maybe if you'd started out by saying, "I heard this the other day and I don't get it."

There seem to be a lot of different opinions in pond-keeping [well, like everything else in life] about how & why certain things are done. Some of the information is common sense [though I rank HIGH in the "duh" factor crowd ], some is based on scientific knowledge [beyond my desire and/or ability to totally comprehend], and some is based on who-knows-what! My mother-in-law was one of those people who "knew" everything about everything, but didn't actually know very much. But if she knew it to be so, so be it -- lots of folks like that out there.

You did just what I would have done, and that is to question the statement, then hit the research, and ask those whose opinions I trust. I want to know WHY we do the things we do, too. For example: "You can't keep koi and plants in the pond together." If you didn't know that koi will decimate your plants, you'd hear that and probably think that plants were toxic to koi [sorry, just the only goofy example I could come up with].

 

[Waterbug]

Where am I reading this? It is one of those everybody knows things that was said to me.

I understand. Without context I'd assume who ever told you this had no idea what they were talking about. Very common. Many people just accept such "facts" and love to repeat it as fact to others. Where you got into trouble was thinking about it and using common sense it didn't smell right. The reason it doesn't make sense to you is because it was nonsense to begin with. Opinions...everyone has one.

 

[Mmathis]

WB, you said it in a nutshell: CONTEXT!

 

[Mmathis]

WB, you said it in a nutshell: CONTEXT!