This is a fish stocking follow up for Chandlers tiny new pond.
Chandler asks
“Can I have bluegill and bass?”
“I was thinking 15-20 bass and 50 bluegill
ANSWERS
First the fish density - He is thinking of adding 15 LMB and 50 BG = pretator to prey ratio 1:3.3. The common ratio is 1:20 or greater for good fish balance and growth.
I discussed the option of fish density and the BG-LMB combo in an above post. Now I want to discuss fish density also known as fish number per acre or carrying capacity. There is a very good thread and informative and educational discussion about Carrying Capacity in the Common Pond Q&A (archives) Pond Boss Forum. It is well worth ones time to read it.
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92440#Post92440

Ponds and farm ground have what is called carrying capacity or production amount. This is the natural ability of the area or size to grow or produce a certain or determinate amount of pounds per acre.The limit is based on soil fertility. This is all based on available nutrients in the ground or pond. Fertility can be measured by testing the amount of nutrients in the water or soil. Generally the more fertile it is the more nutrients that are present in the water/soil, the more crop it can grow per acre.

In water and soil, the ability to NATURALLY grow fish or a crop is basically based on the how available the nutrients are for use by the plants / plankton the base of the food chain. Not all nutrients present are readily available for use by plants. . To make the nutrients most usable by the plants, lime (alkalinity, pH ) needs to be at least a minimum concentration for allowing optimum plant growth.
In ponds and for grazers on the farm we can bypass the need to grow plants as food for the bottom of the food chain and just feed the animals some external food material, In our case fish, we use a high quality, high protein prepared food and this becomes simple farming of fish or animals.

For Chandler’s tiny pond it’s final size is 48x48 is around 2300 sqft or 0.05 ac. He says it is more round than square so maybe in reality it is 1800 sqft (0.04ac) as in the area of a 48ft diameter circular pond.

Stocking this tiny pond for some sort of maintained balance will be a real challenge.

Fertile limestone based soil ponds can generally produce food for growing up to 300lbs of all the sizes of fish at carrying capacity. With good aeration and pellet feeding the fish, poundage can be boosted to 800 to 1000lbs of fish PER ACRE. The higher the fish poundage per acre the more water quality problems will occur and the greater chance there is of a fish kill. Be prepared physically and mentally for this sad day. The most prominent indicator of this happening is the fish will stop feeding on the pellets. Then expect to start seeing stressed fish, then dying fish.

For chandler’s tiny pond, let’s assume maximum poundage of 1000lbs/ac if there is good, careful management. Pond is 0.04 to 0.05 ac X 1000lbs/ac = 40 to 50 lbs of total fish maximum. KEEP IN MIND THAT THE 1000 lbs/ac IS A HIGH POUNDAGE OF FISH FOR ANY SIZE OF POND. Risky business indeed and with this type of fish density a fish kill is always imminent. Those professionals with good experience and preparedness can regularly maintain the 1000lbs and greater high fish densities.

Fish community in small ponds I think is best served with fish that do not reproduce with the exception of using tilapia and maybe minnows or some sort of small forage fish. Reproducing most used larger fish are always increasing their numbers to OVERLOAD the carrying capacity or upsetting the balance of predator prey ratio to the point the results are often poorer growth of fish. Fish overload also trends toward more commonly occurring ill or sick fish, lower water quality, and more algae problems. All often occur together. Always remember - lower fish density and lower carrying capacities always result in overall better pond conditions including the fish.

When using tilapia, pond predators will utilize for growth some of the young-of-year tilapia. Winter water temperatures kills all tilapia and restarts and renews the fishery by annually reducing the total fish poundage. The next years tilapia numbers stocked can be adjusted based on last year’s results.
Stocking of fish numbers can vary based on the fish species used and ones goals. Chandler desires some nice, fun sized predators and good panfishing results for the grandkids. The tilapia and HSB are an excellent fish combo for these goals.

For this tiny 1800 to 2000sqft pond, I would start with 10 HSB and 12 to15 tilapia.
Here are my calculated fish weights for HSB each year when the initial HSB grow to 23-24 inches after 4 years. For tilapia in Texas, I use 14” (1.8lb) as a final end of year size. When do you ever catch a 13”-14” bluegill? So being able to annually catch a 13”-14” trophy bluegill sized tilapia is a real treat.
Plan to have a few HSB die each year due to angler caused deaths. Also realize an oxygen sag due to an over enriched, over capacity pond will first cause death to HSB. Tilapia are pretty tolerant of low DO so they die later if low DO persists.

Year 1 10 @ HSB 12” = 8.7 lbs + 15 tilapia 27lbs = 35.7lbs. A safe capacity
Year 2 10 @ HSB 16” = 21.0 lbs + 15 tilapia 27lbs = 48.0 lbs At capacity
Year 3 8 @ HSB 20” = 34.4lbs + 10 tilapia 18lbs = 52.4 lbs. Over capacity
Year 4 6 @ HSB 23”(6.5lbs) = 39lbs + 8 tilapia 14.4lbs= 53.4lbs. Over capacity.
Year 5 better think about harvesting all HSB and restarting. Fewer HSB to catch, smarter hook shy HSB and less chance to catch them.

Commentary Note. Keep in mind my suggestions above produce a risky high carrying capacity and a good chance of a fish kill if all things do not happen correctly. There is quite a bit of chance for error with this plan.

Fish at this density in small water have to be regularly fed to keep them growing well because this small of a pond cannot produce enough natural foods to feed this capacity of fish. High food inputs, gradually over time increase the biochemical oxygen demand of the pond.

The good thing about this plan is the pond is new and the annual Biochemical Oxygen Demand (BOD) is the lowest it will be in a new low organics accumulated pond. As organics from internal and external sources accumulate, the annual BOD increases with pond age. Aging ponds have greater chances of fish kills for various reasons but mostly from low dissolved oxygen conditions due to the overall high BOD. BOD can vary throughout the year depending on conditions.
If you want to test this fish growing plan with less chance of having a fish kill, then reduce the fish density by any percentage. The lower the fish capacity the less chance there will be of a fish kill and the better the water quality.