Pond Boss Forums POND CONSTRUCTION Selecting a site Pump filter to keep out trash fish

My gut tells me this has been covered before, but I have not been able to locate it.

I have 2 new ponds that I will be filling with a pump using creek water. My initial plan was to fill with the pump, sterilize and then maintain with a well. Problem is, I have punched two wells to 500 and 800ft and have 4gpm and 2gpm respectively (ouch - yeah I know...welcome to the piedmont section of SC).

Anyway, it looks like I will need to maintain the ponds with the creek water and I need a 100% sure fire method to filter the water to prevent a trash fish infestation. I know this creek will have everything from mud cats to gar and bowfin...not good.

I have heard mention of a "sock" for the pump but I'm not sure what the real name for this type of filter is...also, I have no idea if it would work well enough.

I'm thinking a "belt and suspenders" approach will be best and whatever filter I end up with, using it on both ends of the pipe (and maybe even once or twice in the middle).

I am pumping the water approx 3000 ft...the pump is a diesel that gives me 300gpm over that range. The ponds are each about 2 acres but pretty deep (20 ft avg - 30ft at the dam and 12 on the shallow end)...the ponds are close together (200yds apart).

Thanks in advance for any advice. If you suggest a commercially available product, please include manufacturer or retailer details if you know them.

Jeff, I'm no expert on this by any means but it seems a filter to keep trash fish fry out would be so small the volume of water you'll be pumping will require constant filter cleaning, or be massive in size. It may be easier to sterilize and then stock. Once your fish get some size you could use a larger strainer and your predetor fish could control any trash fry that may get through the pump and into your ponds.

Jeff, it would be hard to imagine that any fish could survive a trip through a centrifugal pump, but I guess it could happen. However, I would guess that fertile eggs would be a little more likely to survive.

I can't speak from experience on filtering, as I haven't used a filter yet. I will tell you what I have set up for emergencies, and I hope it gives you some ideas.

My approach is to use a gravel filter bed. I will pump water from the source up to a grassy lane. The water will run about 800ft through grass. It will only run 1"-2" deep and 6' wide. The water will eventually reach my filter, and be filter through about 3-4' of limestone gravel as it enters the pond. I hope I never need to actually use it. If I do get a big dry spell and am forced to use it, I feel pretty good about it. I think 800' of grass and 3-4' of gravel make a pretty good filter.

I have already used the same pump system to fill a 3 acre pond (filled it this spring). I am planning to stock when the weather cools off and will be sterilizing it first.

Note: I have stocked nothing...the pond is only 3 months old....it has beds in it already. I have not seen any of the fish that made them, but I'm sure they are fish beds....so these jokers can make it through the pump....and those had to come in as larger fish to be bedding already.

I didn’t worry about screening on this first pond because I have plenty of run-off to keep it full....I was just looking to get it full and get my PH and turbidity in check before a fall stocking.

BOBAD - I was thinking about a gravel/sand type filter as being the only thing that would handle the volume of water flow needed and have a chance to work.

I did find some "socks" at an online store but they appear to be used to keep larger debris out of submersible pumps...not so much intended for small fish (or fertilized eggs).

So, I guess right now, I'm scheming in my head to use these socks on each end - then a gravel/sand pit that will feed vertically back up a "U" fitting and into the pond (to try to keep the sand in place). I don't think I could go with a long "grassy stream" because of steep banks around my pond....the water would just flow too fast.

I wonder if running the water through a BIG tankless hot water heater could work? Would one of those make the water hot enough to kill off anything living in the water?

Jeff, I think a big sock would work on the outlet side. A fairly coarse steel strainer would work on the inlet side, and would not collapse. It would prevent your sock from clogging up too fast.

I'm thinking something big, like a large laundry bag would make a great filter.

I don't see any reason to sterilize the water. Anything small enough to pass through a fabric filter would be carried into your pond by birds and turtles anyway.

good point on the turtles and birds...3000ft from a pretty major creek/swap isn't very far for them to bring in some junk.

I plan to do annual shock analysis so I guess I can combine my best filter efforts with shocking to remove unwanted species as best I can.

I'm still trying to find some commercially available filters...I can't believe nothing exists for this problem.

Also - to answer one of my own previous questions...it does not look like a tankless heater could get the water hot enough/fast enough to kill the fish and put meaningful flow into the pond.