Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Hybrid Bluegill Pond - Progress & Questions

Hello and thanks for reading. I have a small 1/5 acre pond in South Louisiana, average depth about 4-5'. This is a new pond dug in 2023. In June '24, conditions were finally right and I stocked approx. 700 HBG and 1000 FHM (another 1000 FHM in Sept. '24). I don't see the FHM very much but the pond is absolutely loaded with a few thousand gambusia that showed up naturally (these are very common in South LA ponds). Pond's purpose is to be a trophy HBG pond for backyard fishing anytime. I'm in the extreme South. It's very hot and rains a lot. I run aeration 24/7 due to this. This year, I've already had my first plankton bloom on Feb. 8 when temps were in the 80s for a few days. I'm using phosphate control, beneficial bacteria packets, and the occasional algae defense for water maintenance. I can already tell filamentous algae is going to be my primary algal issue. I was also using blue pond dye for a while but haven't since last Fall. Water clarity is good. Water parameters are good, sometimes alkalinity gets lower and adding lime has fixed the issue each time. I've been feeding Optimal Bluegill since August '24 and the fish are loving it. Feeder goes off twice per day for 2 and 3 seconds respectively. At this point, food disappears in about 4-5 minutes, lots of feeding activity.

Now onto the fun stuff and questions. My HBG are a little over 8 months old now and are progressing nicely imo. Here's some pics:






I know only 1 in 10 HBG are fertile. However, I've seen a lot of what has to be a second generation of HBGs. I have lots of smaller fish that it just doesn't seem plausible they are original stockings based on their small size. Additionally, I'm catching a lot of what I think is a 2nd gen/F2 hybrids. These fish have a different body shape, not the shape of a panfish, but also share some similar traits to the HBG (yellow-ish tipped fins, larger mouth, aggressiveness). Here's 2 pictures of what these fish look like:



What do you think these are? They are very aggressive and have larger mouths. Their scales have black specks on them randomly.

Here's some other questions I have:

1) Should I add more FHM? Is there another type of minnow I should add? Threadfin shad? Golden shiners? Anything that make good baitfish for the HBG.

2) I was told by the fishery where I purchased the HBG that I should add bass 1 year after the HBG for population control. With the amount of smaller HBG I'm seeing and catching, I definitely think it's time to do that soon. But how many LMB should I add to a pond my size? Here's an aerial pic of the pond:


Thanks in advance for any advice. I plan to update here as much as possible to show the progress, particularly at the 1 year stocking anniversary in June '25.

Looking good. Those different looking fish may be pure Green Sunfish (GSF) that washed in with the Gams. Add 25-50 Largemouth Bass to the pond, but I would not add any that were smaller than 4" or 5" or they may be eaten by the HBG. If they had 10" bass I'd add 25 of them. . Once the Bass pull off a spawn (Most likely 2026 for the 4"-6" ones, maybe this year if you add 10"-12" ones) start pulling out EVERY bass that you catch that is over 14" in length. You don't want large bass in there, you want a bunch of small bass to eat the overabundance of small HBG or GSF.

As for what minnows to add, you really don't have to add any if you are feeding the fish. The Gams will be plenty. If you feel that you have to add some, add more Fatheads. None of the other minnows will help you with your goal.

One thing to watch (but it might be hard) is any surface water flowing into the pond. You don't want bullheads, gar, carp or other fish washing into the pond. So, if you can stop more surface water from running into the pond, it will help your goal.

Check the laws there. If it's legal to stock Tilapia, stock 8-9 pounds of them this Spring. They will help control most or all of the algae for you.

Those are real beauties, and a beauty pond too well done.

I can tell you are trying to maximize carry capacity in your small pond and that you have taken precautions to ensure minimum required water quality both with 24/7 and sequestration of phosphorous. I would agree that this would help to keep your water happy for the fish.

I very much like esshup's rec for adding the LMB, both for the recommended size and the quantity. Were it me, I would follow that advice to the letter and do this as soon as I could. You mentioned stocking 700 HBG. I wasn't certain if you meant 700/acre or 700 in a 1/5 acre BOW. But if the latter, that is a very high population density for a trophy pond. They could already be very near the biomass that the feed can support which would mean that growth will slow unless some are removed. How much you are feeding is an open question. I understand 5 secs a day but that doesn't state the daily weight of feed. Can you tell us what weight of feed has already been fed (eg how many bags)? Also would be great if you could test feed delivery rate in lbs/sec.

The lower two fish don't look any different to me than GSF. They don't look like Fx I see commonly around here either. Pretty good chance, as esshup suggested, that GSF made it into the pond with the GAMs in high water. Were it me, I would remove any I caught. I think also, if I were to allow recruits to grow out, I would try to select those recruits that resemble the original F1s the most.

Thanks so much for the advice all. Now that you’ve pointed it out, those two bottom fish are definitely GSF and I have a lot of them in there. I may start pulling out the small and medium ones as suggested. I’m very concerned they will breed and overpopulate.

Understood on the bass. Now to find somewhere that sells them larger sized.

It was 700 for this 1/5 acre BOW. The hatchery said if I have aeration and feed daily, it could easily support that. I took them at their word. I figured some wouldn’t survive but I’ve only found 4 dead fish in almost 9 months. I’m willing to bet the GSF were mixed in with the HBG and that’s how they arrived. There’s no water draining to the pond at all. I have an overflow for rain that empties in ditches and local drainage. And I added a line directly from my well to the pond for when the water gets low.

I can get tilapia here so I’ll consider that as well. Thanks again! I’ll be on the hunt for bass in the coming weeks.

Those are very nice sized HBG. Dandies for just 8 months after stocking them. Your southern long growing season has helped quite a bit to produce excellent growth rates of certain individuals for 8 months in the pond.

You have received great advice so far EXCEPT IMO about the number of HBG suggested to you by the Fish Farm. They are in the business to sell fish for profit and they definitely did that to you. For your trophy HBG goals,,,,, I think they sold you way too many for your goals of - "Pond's purpose is to be a trophy HBG pond". By adding 700 HBG to 0.2 ac (1/5ac) that equates to 3500 HBG/ac. If each one grows to 10"-11" as 1 lb fish, that equates to 3500 lbs/ac. Currently some of your current HBG look to be 8.5"-9"long and at 0.64lb each this equates to a total of 2240 lb/ac. At the end of 2025 they should be growing to 10” and pushing the 3500 lb/ac total fish weight mark. WAY TOO MUCH BIOMASS IN 1/5AC. See next.

This quote was from a prior PBoss thread started by Bruce Condello who lost a whole pond of trophy hybrid striped bass because of too much carrying capacity. Experience learned.
“Natural carrying capacity of all fishes present can range from 40 lb per acre to up to 2000 lbs per acre. IMPORTANT - As carrying capacity increases water quality decreases proportionally.”
Quote from a very food carrying capacity thread: https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92440

Just 1200 -1500 lbs/ac as pellet fed fish is IMO too high and risky business when they are pellet fed and have pond bottom aeration. Normal non-pellet fed, natural total fish pounds /acre is on the upper end around 350-400 lbs/ac for naturally fertile ponds; and sometimes as low as 250 down to 40 fish pounds / ac in some ponds. One can often with very good happy water management and pellet feeding can boost the total fish weight to the 1500 lb/ac mark maybe even 2000 lb/ac. A high amount of feeding to produce very high fish biomass very often leads to water quality issues, excessive algal blooms, fish health stressors and very often unexpected fish kills.

When your 700 HBG are at 10"-11" long (3500lb/ac) you are at 2.3 times the safe fish weight standing crop limit for a pellet fed, aerated pond. Trouble is waiting to happen. When too much carrying capacity is present the fishery is highly stressed and in big danger of crashing that almost always results in a fish kill; partial or major. It will be devastating to have all the work, big fish effort, money and time you have expended so far to end up having dead fish one morning. All that needs to happen for this too high of fish biomass and high productivity set to occur for a kill is in the warmest part of the summer there are several cloudy rainy days and an oxygen crash will occur usually at night. The higher the fish poundage present the more likely that this will occur.

See this informational PBoss thread about pond fish carrying capacity – biomass.
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=201502

This is what I think you should do.
1. Remove fish biomass; quite a bit of fish weight. Weigh every or all the fish removed so you have a record of fish weight removed. IMO the more fish crowding that you can alleviate,,,, the remaining fish will grow to larger sizes that is your goal.

2. You say “"However, I've seen a lot of what has to be a second generation of HBGs. I have lots of smaller fish that it just doesn't seem plausible they are original stockings based on their small size. Additionally, I'm catching a lot of what I think is a 2nd gen/F2 hybrids.""

The smaller individuals could maybe be 2nd generation HBG or they could just be “mutts” as slow growing, low quality of original stocked hybrids. Not all individuals of a population grow at the same rate. Some of your stockers could have been a mixed grouping of lower quality hybrids. Some fish farms do that type of thing - known or unknown.

Remove especially those HBG that appear atypical, maybe 2nd gen and EVERY ONE of those that were considered types of green sunfish(GSF) or don’t look like the biggest HBG you have been catching. IMO this will be ALL the smaller ones. GSF will never grow as big as a good quality HBG. GET ALL THOSE ATYPICAL ONES OUT. They are okay as dinner guests but are not potential trophy caliber fish. They are detrimental and are not wanted to achieve your pond goals of producing trophy HBG. Those smaller atypical ones hinder growth of the best HBG of those destined with genetic potential as trophy category. Release only the biggest ones if you want to produce true trophy HBG in your small 1/5ac (0.2ac). Always keep measuring the lengths of what appear to be the biggest hybrids that you are sampling / catching so you know which ones are smaller and slower growing and ones to be removed.

Look at this way. 400 lb/ac of just HBG each one weighing 3 lbs is 133fish per ac x 0.2ac = 26.6 HBG as 3lb fish(as 13”-14” HBG) in 0.2ac. If your HBG are TOO crowded they will NEVER grow to be those true trophies of 13”-14” long.

Removing poundages allows for more healthier individuals and better growth of all remaining fish. IMO for trophies,,,, it is much better to have a lot fewer bigger, healthy growing fish compared to all dead fish or numerous fish not growing to their best trophy potential. When fish are enduring stress they are not growing to their potential or ability.

3. Some have suggested to stock some juvenile or sub-adult LMB (8”-10”) to be big enough to right away start eating small or new crop HBG. GOOD IDEA. But keep in mind that total weight of bass that are added and as they grow larger (more total body weight) contributes to the pond’s total carrying capacity and reduces the poundage of HBG that can thrive in your small pond. IMO you would not need a lot of 8”-10” LMB probably 6-10 of them to begin with bass stocking. Ponds often have a capacity of healthy LMB that is around 50 lb/ac. So for your pond, 10 LMB 12” long is equivalent to 50lbs/ac. Bass 8”-10” with plenty of food can grow 4” in one year. 9”LMB + 4” growth is 13” and 1.2 lb each x 10 = is equivalent to 60 lb bass/ac. IMO probably too many.

4. For your small pond I would buy a long minnow type seine (50-100ft) to periodically help collect, sample, examine, and remove unwanted fish. This place sells long minnow seines at a reasonable price. This one is durable - 1/4″ Nylon Minnow Seines -4 feet deep x 50 feet long as SKUN5014: The lock-knitted netting in this seine is made of extra strong, multi-filament yarn to prevent runs and fraying. The seine has a delightful “feel” and ease of handling. It is also mildew resistant for longer life – a very good quality seine. The cords are over-edged in the netting for extra strength. The seines come a variety of lengths. He also makes seines longer than 50ft. Ask for custom work. Tell him your purpose.
https://douglasnets.net/product-category/minnow-seines/
Other fish net companies (one I think in LA ) also sell good quality seines that are taller with larger mesh than a 4ft tall minnow seine.
LA net company: https://www.netsandmore.com/products/fishing-nets/seines

5. Also helpful to help remove small fish are fish traps. Z-traps or cloverleaf fish traps either bought or homemade are very good for trapping small fish. BG, HBG and sunfishes readily enter fish traps. Search YouTube for fish traps – commercial and homemade. Larger traps with appropriate sized entries catch larger fish.

6. Seines and traps can help reduce unwanted HBG and lowering pond fish capacity (Standing Crop) so not so many lbs of bass are needed to help manage the numbers of Fx generations of HBG.

7. Please keep us updated as to the progress of growing trophy class HBG. We all need to learn more how to grow all kinds of trophy class fish.

Jake, I’m a green sunfish fan. They will outfight a sissy bluegill any day. At best, they spawn annually. When you hook one, you know it.

Bluegills, OTOH, pull off multiple spawns. 90% of all the fish eggs laid and hatched get eaten before they can spawn. But that’s their purpose. If they all lived, you would quickly have an O2 crash with resulting fish kills.

Don’t sweat the dreaded green sunfish. They’re a bonus.

I'm with Bill. Using a seine will reduce the amount of bass that you will need in the pond.

FOR YOUR GOALS I'd follow Bill's advice and specifically target all GSF and the "mutts".

Pay attention to their feeding response. If they slow down feeding it is 1 of 2 things. Well, 3 things....... 1) they are off trying to spawn or 2) the water quality is starting to tank.3) The water is too hot - but that is easily checked with a thermometer.

Let me know if you want a more enthusiastic or technical tone!