especially if you let them grow to exponential proportions! I let my Hyacenths go and after about 3 -4 months, they actually choked out the pond causing 30 of my 12+ inch Koi to die. This was my fault and felt terrible for the neglect, but this is a lesson that you can learn from.
Keep those babies in check, they are great for filtration and even look nice in bloom, BUT grow to no end!

Damn Ger.
That is terrible. Your koi fish were so awesome/beautiful too!
/sad panda.

-Rebecca

Ok i dont know much about pnds, always wanted one though. I dont understand how the plants "chocked" the koi out? doesnt plants produce oxygen, and consume co2, and fish breath oxygen? what am i missing?

I was wondering this myself, so being the little science nerd that I am- I did some research.
I found this: At moderate levels, aquatic vegetation is beneficial to fish populations. But when it covers more than ½ of the pond, the potential for a fish kill is greatly enhanced. Plants produce oxygen during the day when there is sunlight, but not at night. During the night, plants, fish, insects, and naturally occurring bacteria use oxygen for respiration. If the oxygen produced during the previous day is insufficient to carry pond life through the night, a fish kill will result. As long as the weather is sunny, oxygen production is usually adequate. However, several consecutive calm, cloudy days can reduce the pond's oxygen level to a point where fish may not survive the night. These types of kills usually occur during warm weather. The best way to avoid this problem is to prevent weeds from covering more than ½ of the pond.

Citing - http://www.dgif.virginia.gov


Actually makes a lot of sense ;]

Ok that makes sense! Thanks.