Recent Questions
     Pond Fish

Q. My fish are gathering under the waterfall, some are even trying to
jump it, what gives?

Thank you ,
Denise Vierich .

A. Have you ever been in love? If so, did you feel like jumping and swimming naked under a waterfall? No worries. It's all part of the dating routine for fish.

Q. Our pond has goldfish in it. Nothing fancy. In the past we had water hyacinth and water lettuce floating around plus oxygenators. The problem is the fish eat the floaters. Any suggestions?

Many thanks,
Alma.

A. If you feed your fish, they will eat less of the plant material in the pond. Also, if you add more lettuce and hyacinth, they won't be able to consume the plants as fast as they grow. Imagine if you had to eat nothing but lettuce every day then suddenly someone offered to cook you a beautiful four course meal. You'd probably eat less lettuce.

Q. Dear Dr. Pond,

How deep does my pond need to be in order to keep fish over the winter?

A. Most people think that their pond needs to be built below the frost line in order to keep fish over the winter. This is a very common myth, especially in colder climates when in fact there are thousands of thriving two-foot deep ponds all over the country. The water in your pond will only freeze eight inches down, even in Canada, because of the insulating qualities of the earth that surrounds the pond. If you build your pond deeper than two-feet, you now have a "swimming pool" by most municipal standards and you now must erect a safety fence and contend with strict building codes and permits. A deeper pond only means more work with no real added benefit.

Q. Dear Pond Doctor,

I think a raccoon is eating my fish. Every few days, 2 or 3 more are missing. What can I do to prevent this?

A. When you go out to enjoy your pond in the morning and you notice that a few fish have gone missing, it's very tempting to blame raccoons, cats, and other critters.  Before you go setting up traps, consider the following facts.  Most four-legged creatures, including raccoons, generally prefer to stay dry.  Sure, they may hang out on the side of your pond and try to take a swipe at your favorite Koi or Shubunkin but fortunately, most fish will swim to deeper water out of harms way when threatened.

One predator you do need to watch out for is the blue heron because they don't mind wading in for the occasional Koi canapé. The best solution is to set up a decoy or a Scarecrow motion-activated sprinkler along side your pond.  A surprise jet of water does well in warding of these waders and doesn't harm the bird other than bruise their avian ego.  It's a good idea to move the decoy or sprinkler around once in awhile to keep them guessing.

Giving your fish places to hide also helps increase their odds of survival.  Rocks and short sections of PVC pipe can be used to build miniature caves in the walls and ledges of your pond.  Aquatic plants like lily pads work well too, by creating a natural camouflage that has the added benefit of keeping your Koi cool on hot summer days.

Q. Hello there, 

This is the 3rd spring with my pond and, for the
first time, it appears that a couple of my fish may have some type of parasite (I'm not really sure)???  The one koi looks like it has a small white "tick" attached to his face area.  Fortunately, it is almost gone now. I believe that the warmer water has allowed the koi to defeat whatever this thing was all on his own.  His appetite has been super all spring and he has no clamping of fins or anything like that.  My water quality has been excellent all winter and this spring, so I'm assuming that he picked it up from all the frogs, toads, and birds???  Anyway, my question is do you think I should treat this  fish for parasites or just let him be since he appears
to be healing all on his own?  Many Thanks,  Britt

A. It sounds like the fish had a mild case of  Ichthyophthirius multifilis, otherwise known as Ich or White Spot disease. It might also be Lernaea, otherwise known as Anchor Worm. Click Here for information on both disease conditions.

I hope this helps.
Amor vestry aqua hortus,
Nicholas L. Bott, CIT, CAC