My Plants/Fish are Dying, help

Check the following possibilities:

Are grass clippings or other debris getting into the pond and decaying?

If you allow any organic material to decay in your pond, the ecosystem is thrown out of balance and fish and plants die. Remove dead or dying water lily pads and flowers. Remove any other dead or dying plants. Of course, remove dead fish immediately. Your pond could easily be crystal clear and the ecosystem could be out of balance. Be aware and check your pond at least once weekly. I also advise changing at least 10% of the water weekly.

Have you or your neighbors sprayed fertilizers, pesticides or insecticides?

With termite problem in New Orleans, most people have a pest control service to kill termites and other bug critters. Although post Katrina, the termites have evacuated, we expect them to return forthwith and spraying will begin anew.
Many folks hire horticultural companies who specialize in spraying the garden for every kind of bug, destructive or beneficial. Not only does this practice kill all the good bugs, it keeps butterflies and hummingbirds from visiting, it also can easily kill your pond.

Has the local government done any spraying nearby lately?

This is a problem here in New Orleans because we have mosquitoes and therefore we have a mosquito control program. They send trucks out to destroy mosquitoes. They swear they will not harm plants or fish, but I am suspect of any chemicals.

Is someone painting or scraping a house or car in the area?

Paint from the house, especially lead paint, can get in your pond and kill everything.


Has cleaning been done on surrounding driveways, decks or walkways and run off into the pond?

I include this only because I was at my wit's end several years ago trying to figure out why I could not keep a client's pond healthy. After months of investigation, I finally asked a housekeeper if she was cleaning the surrounding patio. She said, "Of course, I scrub it and hose it down every day." OK, there was my answer. She stopped and the pond was healthy again.

Did someone feed the fish too much or the wrong thing?

Feeding goldfish is probably the biggest problem pond people have. All of you want to feed those poor fish. Those poor fish need to eat what is good for them; submerged vegetation, algae and mosquito larvae. Please make them work for their room and board. Koi must be fed and live in a pond with filtration.

Did you use a new concrete block to prop a water plant up? Use bricks or aged concrete blocks?

Lime can leach out of the concrete and quickly throw the pH into the stratosphere.

If any of these events have occurred, change the water immediately. Don't forget the dechlor.

Pond Filtration?

If you have Koi or if you feed your goldfish, you MUST have filtration of some sort. There are many filters on the market from a plain sponge type to biofilters with UV lights. I have used them all and find that the very best is a biofilter installed outside the pond with a UV light installed in conjunction with it. (A UV light is not effective with blanketweed or String Algae.) So if you are going to feed those fish or have Koi, think about using this filter. The downside of these bead filters is the cost. They can run to $4000.00 with the flick of a fish's tail. There are cheaper ones that work just as well, but it's more work to keep them clean and running properly.

If you wish to build your own filter, it is quite simple using a container of some sort and filling it with some sort of filtration medium like lava rocks, sand, gravel, etc. I use the coarser material at the top of the filter (where the water goes in) and the finer material at the bottom. Much of the time lava rock or bioballs are sufficient.

You must get the water into the top of the filter- pretty easy if the fliter is in the water and suck it out of the bottom with the pond pump. This can be accomplished with a simple tap that attaches to the intake of the pump. You can also just put the pump in the bottom of the container, and put the lava rocks or whatever filter media you use in a mesh bag and not have to worry about a tap of any kind. Your cost just went down to the cost of the media plus the cost of the mesh bag. Just be sure to protect your pump intake so lava rocks do not get into your impeller.

If you do not feed your fish, you need no filtration at all. BUT you must provide natural filtration. The best way I have found is to use anacharis as a submerged plant. The anacharis grows faster than the fish can eat it, so the pond becomes a natural ecosystem. And you must keep about 50-60% of the top of the pond covered with shade. You can do this with floating plants like hyacinths, water clover, water poppy, parrots feather or water lilies. If your pond is in the shade already, you do not need so many floating plants.

Many chemicals are sold that promise a clear pond if you add the chemicals. Some of the time they work. For the most part they do not. They kill algae. The dead algae sinks to the bottom and leave no available carbon dioxide for the other plants. They die and so do the fish because there is no oxygen for them to breathe. If you do not use chemicals, this problem can be avoided before it starts.