Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Can copper sulfate crystals kill green sunfish?

If I were to intentionally overdose a pond with copper sulfate, would it work? Read up on Rotenone, but it's too expense for me right now. Anything else I could use on a budget?

https://www.tractorsupply.com/tsc/product/applied-biochemists-copper-sulfate-crystals-15-lbs

Back story: Drained a 1/2 acre bream pond bone dry for renovation last fall and haven't restocked it yet. It's finally full from rain water , now we have 100 or so 1'' green sunfish swimming around. Guessing wading birds moved them here. We need to kill them off before restocking with coppernose bluegill.

My 3'' trash pump would take ~44 hours to drain plus $100 worth of fuel, but the main thing is I have to wait for it to fill up again.

Any ideas would be greatly appreciated.

Thanks,

Mark

How deep is the pond? Do you have a average depth for calculating the water volume. You should have a good volume estimate for whatever dose of chemical that you use.

Hi Bill, Thanks for the reply. 8' max depth, but probably averages 6' overall. Dimensions are about 140'L x 140'W or approx 800,800 gallons.

http://www.pondvolumecalculator.com/

I've been reading that skin fish are more sensitive to copper sulfate, but can't find much info on nuisance green sunfish. Any idea on reaction time? I'm guessing it would be best to treat the water right before night time to deplete the most oxygen.

Here is a link to a Pond Boss discussion on alternatives to rotenone.

Hydrated Lime for Fish Kill

IMO, you will have better success if you somewhat reduce the volume of water in your pond.

The hydrated lime will pH shock most of the living things it interacts with (except maybe the tuberous rooted plants). Be sure to get a current "normal" pH reading on your pond prior to any changes. It is "time of day" dependent, so maybe take it at two different times and document the time in your notes.

Is there a level to where you can draw down your pond below most of your shore plants, yet still have enough water depth to start your re-stocking plans on schedule - even if you do not get more rain?

For example, can you can draw it down 2-3', then treat it. Once your pond goes back to normal pH you can proceed with your fall stocking plans if you still have enough water to safely start the fish. Hopefully, you will get some fall rains and get back to full pool fairly quickly so you can have happy fish!

P.S. Do you have a low area adjacent to the pond? Starting a siphon is easy and cheap. You can readily drain the pond even if you don't live there. Probably slower than your pump, but I don't think you are in a time crunch?

Just set the intake side such that it will start sucking air before it can drain the pond below your desired level.

I agree with FishinRod's notes above. NO matter what you are doing do your good homework.
Also CuSO4 will not reduce the DO in the pond water. Besides GSF are very tolerant of very low DO. Darn things can live out of water for over 15-20 min and still live. Copper is a toxin that kills the fish it does not affect the DO. Copper that would be added will never leave the sediments and remain there as a potential problem until the pond sediment is removed. Cu is stable in the environment as copper bound substances; does not rot nor deteriorate. Also alkalinity of the water determines the reactivity and killing ability of dosage of CuSO4. Different species of fish have different tolerances to copper in the water. Trout most sensitive and bass most tolerant. All other species in-between the low and high doses.

Another treatment the US Fish & Wildlife Fish Hatchery Management book says to kill fish and disinfect and kill "wild" fish in the hatchery pond besides using rotenone and Antimycin is to use Chlorine in the form of HTH at a concentration of 5ppm. Important make sure what chlorine you use is the right stuff and dilutes to the final concentration in the pond to the 5 ppm concentration. You may need help from sort of chemist or professional applicator for this. IMO I would use a higher concentration of 6ppm AND make sure the entire pond volume gets the 6ppm dosage. They say chlorine kills most wild species of fish. If you don't do everything correctly,,,,, all your time, effort, and money are wasted and you will likely have to do it all over again. They claim chlorine deteriorates fairly rapidly (1-2days) and looses toxicity after several days to a week depending on pond conditions. Water should be tested to see if fish survive before restocking.

Be forewarned. NO matter what method you use it is SMARTEST to LOWER the pond level to 1/2 or more so you

1. don't need as much chemical

2. make sure all fish are forced out of all shallow shoreline areas into the deeper basin. GSF are very tolerant and famous for hiding in shallow shore nooks and crannies to escape harsh conditions. Force them out of the shallows into the bottom bowl of the pond and no place to hide.

3. fully circulate all the remaining water (pumping or aeration) so all depth areas get the full concentration or dosage of what ever chemical you use.

Thanks for sharing, I was unaware of this method. I could live with draining the pond down to 1/3rd or 2-3 ft.

Is this the right stuff at Lowes for $16 per bag? If so, how many 50# bags would be required?
https://www.lowes.com/pd/QUIKRETE-50-lb-Hydrated-Lime/3567274

Thanks, I'm very familiar with calcium hypochlorite (pool shock). I use Chlorine to sterilize rainwater runoff tanks that collect from my gutters @ 1ppm.

For $100, 24 bags would treat 240,000 gallons @ 5-10ppm and I could draw the pond down to about 200,000 gallons for good measure.

https://www.amazon.com/DryTec-Hypoc...p;hvtargid=pla-4583726554502642&th=1

BreamAngler,

Do you mind answering an off topic question in this thread?

My ponds and creek have been going dry during our long-term drought. When they get critically low, I pump water to a bunch of tanks so I can keep watering my tree plantings.

However, the small initial amounts of algae proliferate greatly in the tanks and clog my drip emitters.

How would you treat the stored water in the tanks? When is that water subsequently safe to put on newly-planted trees?

FishinRod,

I would put a spin down filter inline with the drip emitters to prevent clogging. You can stay on top of algae by putting a shade over your tanks and/or using chlorine. Most water companies use chlorine up to 1ppm to get water safely through rusty pipes, then we drink it and water our grass/garden. Low chlorine dosage is the key. You can use unscented liquid clorox or calcium hypochlorite (pool shock granules) to do the job, just get your mixture right and confirm with chlorine test strips. Good news is you can smell chlorine in the water when it's too strong. Shock your tanks after you water your trees, and as the days go by, it will evaporate and chlorine ppm come back down to safe levels before it's time to water trees again.

https://www.amazon.com/Rusco-Vu-Flo...7e5845d&pd_rd_i=B018HFRYXA&psc=1

I use 1/4 cup of unscented liquid clorox to treat a 275 gallon tote/tank. Calcium hypochlorite (pool shock) is better for bigger jobs, because once the bag has been opened it loses potency quick.


https://www.cleanwaterstore.com/res...to-add-to-storage-tank-to-kill-bacteria/

Hope this helps...

BreamAngler - When you use / apply the granular calcium hypoclorite does it need to be dissolved first? If you just toss in the granular and it sinks how do you know it gets distributed throughout the remaining pond bottom that has water. Do you have a way to circulate the pond water after applying the calcium hypoclorite to insure good distribution of chlorine?

Whatever method that you use,, I would first test the concentration that you plan to use to verify that it kills several GSF that you have in a tank or tub of known water volume and chlorine concentration.

When using calcium hypoclorite for water tanks, I shake up measured granules in a one gallon water jug 1st, then pour mixture into tank after it's dissolved. This step isn't necessary for pool owners since they have pumps/circulation. For this pond application, I will probably setup trash pump intake close to the bank and pour chlorine mixture on top of pump strainer and direct outflow towards the middle of the pond.

Great idea on the test kill. I'll bait a minnow trap with bread and see how tough they are before wasting bulk chlorine.

I have read about some fish kill treatments not being successful, and thought: "How hard can it be to mix your chemicals to the proper concentration?"

However, after I read Bill's post above, and realized that the chemical must be perfectly distributed. Only then, did the little light bulb go on over my head.


I think he is worried about you not getting a toxic level of chemical to every GSF's hiding place.

Do you have a small boat with an outboard motor available for use? I have seen a number of posts on Pond Boss where people used the prop wash to really mix the waters throughout their entire pond.


P.S. Thanks for the water treatment notes above. I have imperfectly excluded sunlight from my tanks, and thought a little chlorine treatment would be an easier way to control the algae.

Yes and does in water with low alkalinity. But I would not suggest CUSO4 as a good method to kill fish (hydrated lime and rotenone are better).

I wouldn’t worry about the green sunfish. They only spawn annually and bluegills have rolling spawns. Also, when caught, they will out fight a sissy bluegill every time. I’ve had them, along with bluegills, for over 20 years with no ill effects.