The tilapia will "flash on the bottom of the pond and consume the rotting leaves incidentally to eating the bacteria growing on the decaying matter. This causes an aeration effect, bringing oxygen for the more beneficial and faster digesting aerobic bacterias, plus the disturbances provide fresh new surface areas for the bacteria to grow on, again speeding the process but more importantly, moving the nutrients up the food chain. Raking will assuredly speed decay, but the nutrients released will be available to all other plant life and can shift the nutrient load in the pond into another potential problem.

Stocking tilapia at a rate of 100 pounds+ per acre the first year will normally remove about 12 or more inches of organic muck, along with probably every other plant in the pond. After the first year, stocking rates can be drastically cut back to find the maintenance rate you desire.

RC, I can't really answer your question. It all depends on what preferred tilapia foods are available. Bacteria is high on the favorites list, but it takes a sustained foraging effort by the tilapia to put a big dent in muck---usually an over-stocking rate. Regardless of the stocking rate, tilapia will "flash" the bottom and aerate the muck to a degree which will speed the overall process, but it may not be faster than the incoming debris. In other words you may gain some depth OR you may lose LESS depth each year with a standard stocking rate.

"Flash" is when the tilapia slap the bottom of the pond with the side of their body to knock small bits of detritus and bacteria into the water column where they both filter out and eat the bacteria and detritus.

Last edited by Rainman; 01/26/10 11:48 PM. Reason: define flash as I used it