Woody and Rick :

Thanks for posting . I want to make a couple of points first and then explain.

Rick--excellent questions and answers. I think you got it exactly right . My thoughts on tilapia also but I am not an expert on them. It may well be that they fill a niche in the food chain { eat only that which BG don't eat} but I thought when small they ate plankton. There is no way anyone could possibly think that your questions were ignorant either in the sense of lack of knowledge or lack of being smart. You made the points in one paragraph that it took me a page to make.

Woody thanks for the info. It sounds like you are doing a good job of managing your pond. I will try to help where I can. It may be that your pond is working at max. capicity.

Before I forget most states have fish biologists in connection with their cooperative ext. services . That may be a source of eyes on help . If you use this or any other source of help , in advance { before they make an appointment to look at the pond} give them a written history of your pond with as much info as you can remember. They will be glad to get the info so they can prepare and focus in on your problems and they will know you are serious. They will not have the detailed knowledge of how your pond works like you do so any help you can give them will increase the chances that your questions will be addressed. If any expert gives you an answer that does not make sense to you check it out first. They may have missed something that you know about.

My thoughts/explanation. First DO problems in small ponds are not my strong point. I can only guess because I have not seen your pond and have no DO profile . My "guess" is that because you are so actively managing your pond with fert. and feeding with a dense fish population your pond is like an acquculture operation. That is it is running at full capicity . Your pond is a biological engine running flat out . We all know that if you run a car engine flat out for to long it is much more likley to break . A pond has a max carrying capicity --a biomass limit. It works off of water , soil , oxygen , co2 , food {nutrients} , light and heat all in combination . Because they all work together and depend on each other being there , if one is in short supply the engine does not run right. Like a car engine with the wrong fuel/air mix or bad spark plugs.

Does your well water have enough oxygen ? If not that could be part of the problem . I suspect that you don't have any real problem that moving away from max. output won't cure. What Rick said may be the exact answer. That is let up on the gas a little. Consider only fert. enough to get 24-30 in visa. and , if you need to feed a little more. Under the conditions you described this should lessen the chance of DO problems. I know how hard it is to control a bloom even when you try. So many uncontrolable factors like weather , rain/no rain , clouds/sun , hurricanes etc. My suggestion is to start each spring slow on the fert. so you don't get a build up of nutrients in the water that may explode when july/Aug/Sept. with high heat and low rain arrive. Because you are using areation and may have a build up of nutrients in your soil which come up in the areation you may want to wait to see if your pond needs fert. to start off with in the spring. You could get your pond bottom soil tested to see what , if anything , it needs or does not need. We always take soil samples so that we have a baseline to work from. One concern I usually have with increasing visa. {light penetration } in the warm part of the year is the potential for FA {algae} growth . You may well have this covered with the tilapia -- a good move. You may have enough fert.in system to last till fall. I see that Greg has come on board and also answered some of your questions while I was writing. Please note that he has some of the same points as I do on natural fertility . If you do back off on the fert/# lbs, of fish you may need to eat a few more of the BG and bass and tilapia to lower the #/lbs of fish in the system prior to reducing the carrying capicity in order to keep the remaining fish fat and happy. Keep us posted. ewest

ps . I agree with Greg that water sol. fert is much better. It is easy to use and works faster which makes it much easier to do a little at a time. Also liqu. fert. is much easier to make a mistake with ie water ratio and getting to much in one spot. in the pond . Water sol. is like throwing out sand easy to control amount and location. After a number of years of testing we use water sol. most and then use some grainular on platforms for its long term dissolving ability.

pss thought I would add the below info by Bill re aeration :

Bill Cody
Lunker
Member # 24

Member Rated:
posted May 24, 2005 08:01 PM
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Does aerating affect the algae bloom?. It all depends. Numerous things come into play with this feature.

1. Strength of the mixing currents and what percentage of the pond's volume AND surface acreage is being turned over or mixed.

2. Nutrient load and nutrient reserves in the pond which provide food source for the algae are important stimulators of the bloom.

3. Water clarity and bloom density (number of organisms per milliliter are important in affectding the bloom.

4. Frequency and length of time that the aerator operates. Continuous running would usually cause planktonic algae to be in deep water only a relatively short time.

5. Algae speices. Each species responds differently to the variables. There are thousands of species of planktonic freshwater algae that could be living in ponds across North America. Some will be supressed by the circulaton affects whereas others could or will be stimulated by the circulation. Others such as certain fragile colonial types could be broken and disrupted by the movement and currents; ddurable colonial forms are very tolerant. Some algae tolerate low light conditions very well. Some algae go into suspended physiology during low light or low nutrients only to be reactivated when conditons improve.

6. Weather conditions and season (temperature / daylength) can be important players in how well algae survive regardless of aeration and or movement or depth of the individuals.

7. If I really thought about this and did some book searching I could find other reasons.

8. Basically - As a bottom line, It all depends. This is why one person can swear the aeration solved his algae problem and in another's case the aereator stimulated their algae bloom.

[ May 24, 2005, 08:08 PM: Message edited by: Bill Cody ]
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