Water hyacinth

[kiky]

If I remember correctly, the first time I read about water hyacinth being put in a koi pond, was in a thread by Maurice. He even posted beautiful pictures of it with flower in full bloom. Now, I noticed in recently posted pictures of Momotaro auction that there is water hyacinth in both indoor and outdoor ponds.

How beneficial is it actually to pond water? Does it reduce nitrite/nitrate level just like other plants? Or is there any other function?

[DNNS]

Hi Kiky,

Water Hyacinth (Eichhiornia crassipes) indeed reduces your nitrate/ammonium/phosphate levels. But it has even more qualities.
It's an important plant used for phytoremediation, the take up of some heavy metals. We shouldn't exaggerate the effects of phytoremediaton, but all the little help is welcome of course

Dennis.

[Werner]

Water Hyacinth along with Water Lettuce are very good absorbers of nitrates and are used most effectively in plant filter application where water flows past their roots rather rapidly. Adding these floating plants to a Koi pond will usually result in dead plants as Koi love to root around in the roots and will strip the roots bare in short order killing the plant.

These plants originated in Brazil and are banned here in Florida because of their rapid growth in sub-tropical climates. They have taken over some freshwater waterways here and are costing the state millions of dollars to control. I believe your climate is similar, so you may want to check with your authorities about importing this plant.

[dick benbow]

FYI-for big grow ponds the raft of plants provides necessary shade in addition to their ability to clean water. they also can carry Parasites and must be cleansed prior to being placed into your pond no matter where the source.

[kiky]

DNNS,
thanks for the information. I put the plants only less than one month ago. They seem to grow quite fast. I hope it won't be long before I have sufficient quantity to have any impact on water quality.

Werner,
I did'nt put the plants in the main pond. I put them in a small side pond through which the water returns to the main pond from the filter. So this way the koi cannot reach the plant at all. I didn't know about its origin. I thought it is native to my country! As we can find this almost anywhere here - in the drain, in natural lake, in rivers etc. Of cource we can also buy from plant shops very cheaply.

DickB,
thanks for the precautionary words. Yes I disinfected them, by soaking in chlorinated water for several minutes, before putting in the pond.

[bekko]

Crowd them tightly together to get them to bloom.

Remember that to get long-term nutrient reduction, you need to remove plant material from the pond. The dead leaves will decompose and release all the nitrogen which is stored in them back to the water. Dying leaves or whole plants that are removed from the pond represent a nutrient export which helps to counter-act the nutrient input via koi feed. Hyacinths grow quickly and you will soon be able to throw away about 10-25% of them each week. As you throw them away, imagine that you are throwing away fish waste.

steve hopkins

[kiky]

Hello Steve,

Thanks for the added information. Yes they do grow quite quickly. However I now find that most of them are yellowing. I was told that the first few water hyacinth I took must have come from more shaded place. As my pond is under full sunblast, they need some time to adapt to new condition. Sooner or later they'd be back to normal. Is this true?

[Ryan S.]

I used to keep some of these in ponds (Koi love the roots, so most where in my waterfall area), however if you are running trickle tower or shower type filtration the nitrite/nitrate will be to low for the hyacinths to survive. I used to rotate the plants every couple days after there was a TT on one pond but not my other small goldfish pond but after I put a TT on that pond I was out of luck. After that, I setup a mortor tray with miricle grow and used it to rotate the hycinths inside and out of the pond. To much work so I didn't bother this year. Late in the season they die off so fast its easier to remove them then to constantly pick through the dying leaves.

[MikeM]

Hi Kiky. The change to full sun will cause bleaching. In full sun the hyacinth will be a bright yellow green with the leaves held compactly. It full shade, they are a dark green with longer, elegant leaves. Ryan is also correct. Hyacinth are heavy consumers of nitrogen. The better the water quality, the more yellow they will appear. Nitrogen deficiency [a good thing in a koi pond ... that's why the hyacinth are being used] generally shows as uneven striping in the leaves, as opposed to an even shade of yellow-green over the full leaf. As long as the hyacinth are multiplying rapidly, just keep tossing the old ones away.


RYAN: Welcome! it is always great to have new posters join in.

[bekko]

I'm not sure about the yellowing, but sun scalding is possible. It is more likely that you burned them with the chlorination, but they will grow out of it. I clean them by dipping in a soap solution. Nutrient deficiency can cause yellowing as well, but that is seldom the case.

Also, watch for spider mites - water hyacinth's worst pest. If they have spider mites, the leaves will develop what looks like a golden-brown surface crust, even though the leaf is still rigid and upright. This is from the mites piercing the leaf to feed on the liquids within. In extreme cases, you will see what looks like spider webs covering parts of the leaves. The mites can be washed off with a water spray or by dipping in a soap solution and then rinsing in clean water. You can also pull away the discolored leaves before dipping.

I don't think you have to worry about killing them. If you do, you may be able to make a fortune selling the technique.

steve hopkins