Pond Boss Forums GENERAL QUESTIONS Muddy water Side effect from Tilapia

Newbe question here.

A little history.

I'm midpoint through my first full summer with my newly acquired 35 yr old neglected 1/2 acre pond. The pond has an abundance of muck caused by accumulated leaf debris. Very little silt from runoff. This spring I added 11 lbs. of Tilapia to try reduce the amount of algae that I had last year and they are doing great. I haven't had to rake out any algae so far this year.

Other than the TP I have few LMB and many BG and BC. The TP are reproducing like crazy.

Now the question.

Now with very little algae my water has a brown tint to it. This spring it was very clear. It's not a light brown clay but darker. I did do a jar test and was able to clear it with some alum. My thought is maybe the TP ran out of algae and are now eating/stirring up my muck. Which is a good thing and over time my water should start to clear.

Any thoughts?

I can't answer your question but can tell you my experience. I find that as the weather changes the pond will change also. It is not uncommon for my pond in late summer to get a blackish or brownish look to it.

I've just always assumed it was another form of algae that responds to warmer water temperatures or a die off of the greenish type algae. I don't really know but know the creeks and other BOW's change with the season and temperature also so never was too concerned about it.

gklop, Tilapia will stir up the bottom, but more from nesting than foraging. Tilapia will suck in detritus, filter out and chew what is edible, pitting out what isn't. If your pond clears naturally, I've never seen the Tilapia "muddy" the water very much at all.

The Tilapia will also pump oxygenated water into the leaves on the bottom to help aerobic bacteria break the leaves down faster. Tilapia like the bacteria more than the leaf litter.

As for the brown color...I have seen a lot of ponds this year that have brown algae growth rather than green planktonic growth.

When you used alum in your jar test, did the floc float before sinking? If so, it was an algae or other organic life, and not clay or inorganic solids.

The Tilapia I have follow me around like puppy dogs waiting for me to throw them a fish food treat. They are fun to watch come flying towards the sound of the 4-wheeler.

I have about 2/3 white and 1/3 blue. The white ones are sure easier to spot in the water, but once I spot the white ones, the blues will be right in there with them.

They seem to constantly be swimming in open water (In the ponds where I have no large predators. The few that are in my big pond hug the bank like the smaller BG I assume because of the LMB predation).

I assume they are filtering algae out of the water? Come to think of it, in the two smaller ponds there is little to no detritus or FA growing on the bottom. So maybe that is all they have available. I'm feeding them good with the hopes to transfer them to the big pond soon. They are getting to about 5-6".

The brown color, other than a form of planktonic algae that has filled in a niche the FA occupied along with some suspended solids, could also be zooplankton.

Bill Cody?

My trout pond in the summer's I have left it devoid of fish, and turned the well off, took on a brown color. Sent a sample to Bill Cody and he indicated it was predomiately a benign golden algae species.

It did a great job of keeping macrophytes at bay.

Zooplankton would be a good thing, I would assume, in a pond with a lot of fish fry looking for something to eat.

A caution with a pond full of tilapia with no predators in a warm climate. My tilapia have spawned like rabbits. You can expect spawning every 4-6 weeks if conditions are ideal from what I have read. I have had at least 4 different spawns already judging by the size classes I am seeing. I am currently trying to add predators slowly to avoid mass overpopulation. It also helps that they are tasty and the kids love to catch the larger ones.


The color of my pond is also "browner" I suspect from the orgy below.

Since the op is in Ohio they should all cold kill, but just thought I would throw out an observation.

Side effects include really bad taste and uncontrollable bowel movements.

Very true. For those of us that produce fry of various species in a pond, zooplankton is what we shoot for. Sometimes is much more difficult than it appears.

Gallop, do you remember what size your tilipia were when they started reproducing? Did you buy ones already large enough to reproduce?

I just bought fingerlings (1") because a place had them that was within driving distance and my wife and daughter wanted a road trip to KC anyway. I knew they would never get big enough to be of much use for algae control, but got them more as a novelty and get a little experience with them. If I like them, will probably try to get some breeder size next spring to go directly in the main pond.

My largest ones are at least 5" now and I wonder if they are not getting close to spawning size/age. Right now about 95% of what I have are in ponds with no large predators. When they get spawning size would like to get at least quite a few of them over into the main pond so they could produce some LMB feed with their offspring before winter. The ones I can't catch will continue to feed and try to capture them about November when the water cools for human consumption. At least that is "the 'current' plan". The tilapia may have plans of their own.

Those little suckers are like rockets. Early on I trapped a few when they were about 2" in minnow traps to move some to a larger environment and also netted some out of my wifes 5'x10' concrete pond by the house where we raised a few for a while. Those things would jump out of the bucket like nothing. Was fishing in the sediment pond today (to sample my RES growth) where most of the 5+ inch ones are and must have spooked one near the shore. It flew out of the water, clearing the water no more than a foot, but traveling horizontally in the air about 8 feet before entering the water again and zoom...... gone. They will come right up to me when in the 4 wheeler but if I step out they keep their distance about 10 feet. Will eat pellets up to an imaginary line, and then sit and wait (while stealing an occasional pellet) till I back up or leave. They are a curiously unusual fish. In this hot weather/water, while the BG languish in the heat of the day, the tilapia seem to just hit their stride, moving around the pond all the time looking for something to eat. I feed them every time I go around the pond (sometimes 3-4 times a day) and they always seem hungry.

They have been fun. Don't know how I'm going to catch some to transfer, but hopefully with a seine or lift net or something. The ones in the pre-sediment pond should be easy (famous last words). It is only about 20x40 and I should be able to seine it easily, even pumping it down a little if needed. The 1/10th sediment pond is going to be more of a challenge.

I have a few in the main pond as I transferred some there at the 2-3" stage. But I think the LMB got most of them. Figured they would. I see a few of the whites left and can't tell about the blues. The blues look too close to the BG to be sure and since they are few in number the tilapia tend to school with the BG in the main pond. So it is hard to make out if I have any blues in the main pond or how many.

It has been an interesting experiment. So far, glad I did it.

Think I answered my own question about reproduction.

Was feeding today and noticed what looked like some weird minnows along the bank. Looked like they had the remnants of a yolk sack hanging down. Too big to be FHM FRY. I think they must be tilapia. I netted a dozen or so and put them in my wife's concrete pond and will feed them long enough to see for sure what they are. If they are tilapia fry, they will grow quickly to a size I can be sure.

Got the cast net out (which I previously have had very marginal luck with) and managed to catch two whites and two blues that were about 6" long and put in the main pond. Also caught a couple of 5" blues (some were smaller that we had raised in an aquarium instead of the pond and had been transferred to this pond when they over crowded the aquarium). Actually did a decent job of casting the net. Then later in the day tried it again and must have forgot all I knew because all I could throw was taco nets.

The tilapia wised up and I hardly see them now when I drive up. They learned the cast net trick pretty quick. Will have to go to a seine or trap or some other method of catching them.

Snrub have you tried throwing out a cast net a few hours after dark. We sometimes do this when it's hard netting fish in the day and it seems to work well in the 3-5ft shallows. Throw them in a holding tank till the morning when I can sort without a flashlight.

Rainman, I'm not sure if it floated before sinking or not. In reading what others have posted it might be brown algae. I have very thin layer of brownish scum on top that almost looks like oil sometimes. I thought it was just pollen. I'll redo the jar test and see. Thanks for all the input.

Gklop

Had not even thought of that possibility. Might try it.

I do go out at night with a flashlight just to see what is going on around the pond sometimes. See lots of small BG sleeping in the shallows, so I can see where the cast net could work.

Thanks!

JKB, Tilapia, at least the species used here, are fairly unique among fish in that all studies I have seen show Tilapia flesh is not affected by foods eaten. Contamination during the cleaning process, however, is somewhat easily done, and can let intestinal fluids escape to taint the meat with myriad "off flavors".

Snrub

I stocked most at 2-3 inches. Had ~ 8-10 breeder sized 6-8" fish from a friends pond. We have harvested every 3-4 lb fish we catch. I prefer a pellet fly, they are really good fighters on a light weight fly rod.. The growth in 1 year was amazing to me. We do have feeders set up.


My son and I ran a 4x20 seine twice on one edge of the pond to transplant some to a friend. We caught between 200-300 up to around 4 " and we aren't exactly masters of seine netting.

I have found the meat to be quite tasty after letting them purge in a tank for a couple days while changing the water a couple times

They really are tough bastards, impressive food to weight conversion. I wouldn't want to meet one in a dark alley

How big will a Tilapia grow in E Texas? Length and wt? I added them to the pond last April. They were in the 4 to 6" size and are feeding at the feeders using Cargils 42% protein feed. And I see little to no FA in the pond so I am guessing they are feeding on it also. I see a lot of the Tilapia fingerlings around the pond from their spawning. What size do u guys think I might see in November when the water starts to cool down?

Tracy

Is it necessary to purge the tilapia? We never purge CC or BG.

Just wondering, where they eat lots of algae, if the purge process is needed or just optional to make sure they taste the best. They taste ok without purging?

No, it's not necessary, but easily done. The Tilapia flesh is bland and will take on the "seasonings" put on it. Unfortunately, Tilapia intestinal fluids, with foods present and being digested, are extremely acidic. The slightest rupture of an intestine while cleaning will easily let that acid strongly "season" the flesh.

The best way to purge is putting the Tilapia in 5 gallon, net covered buckets with a slow flow of well water for 3 days or till no waste is seen in the water. Tilapia produce an unusually strong digestive acid with a pH ~1. Tilapia have only have a small, acid pumping bulb that acts as a stomach. Food is digested in a unusually long intestinal tract with the overly strong acids and enzymes that allows the Tilapia break down strong protein barriers from nearly anything eaten.

The added benefit of using well water to purge, is the water temperature is often 58-60 degrees, which greatly slows metabolism and acid production.

TGW1 - Expect your tilapia to grow about 1mm per day; sometimes 1.6mm/day in optimum conditions. This will be informative for you to report back here in Oct-Nov with some measurements and maybe a few pictures?.

Great information Rex! Had no idea that tilapia had those differences from our normal pond fish. That explains how they can use food sources (like FA) that other fish would not gain much nutrient benefit from.

Thanks!

Tilapia are definitely chow hounds.

I don't know much about Tilapia, but I agree with Rex's assessment on the taste. Bland....tastes like whatever you prepared and cooked it in to me.

The differences in the tilapia intestinal tract, and ability to eat any food, including "non-nutritious" foods, is probably why many state biologists feel tilapia will compete with and displace all native species. This danger is only on paper, and in the pond, Tilapia most prefer foods no other species can/will eat and get nutrition from. And of course, once the tilapia eats the trash plants, the other fish thrive on eating the tilapia.

Sparky, try baking some slathered in real butter, with sun dried tomato and lemon zest along with some Tuscan garlic salt blend and black pepper seasonings.

I'm not a big fan of fish, but had some Tilapia described above and all I can say is.....YUMM, gimme more!

The 200 blues I grew out from fingerlings last year in my aquaponics system were some of the best tasting fish I have ever had.

Bought some imported tilapia from overseas at the local grocery store a few years ago that had a strange flavor to them.