The water temperature is too low. It needs to be a minimum of 60oF. Its better if above that. The light needs to be very close to the surface. About 8 inches. It should be on 18 hours and off 6. Sandy

Sandy,
Thanks for the advice! I'm going to town tomorrow so I'll see about getting a heater for my tank. Also, I found out that my light is NOT a halogen, it's a flourecent. Will that make a difference? Thanks!

Sara

The problem is that your plants are tropical and need warm water and loads of light but goldfish are cold water species and don't need or want such warm water.

I've tried water hyacinth in a lighted 75* aquarium with tropical fish and they still died. Ditto water lettuce.

I've also tried them in a 70* pond in my heated greenhouse and again they both died.

What about getting some anacharis also known as goldfish grass from an aquarium store? It won't require heated water.....

I have tried several times to overwinter hyacinths under artificial light. Oddly, they all died under fluorescent light, but thrived under incandescent light. The fluorescent lights were supposed to be plant lights. I don't understand why the fluorescents didn't work, especially since other plants seem to like the fluorescent light.

Actually, my best success was just putting the plants on a south facing windowsill. I know all this is different from trying to grow them in an aquarium, but this might be helpful.

I have had success overwintering hyacinths in a rubbermaid container with water and an aquarium heater set at 70 degrees.
I also put the container in a south west facing window.

Thanks for all the advice! I now have heaters in my tank and the water is setting right at 70 degrees. I'm not sure if I'll have to turn it up farther or not. My Dad found some "plant" lights and we put those up, lowered them closer to the plants, and I increased their daylight hours to 14. We've noticed that the roots are now reaching more downward than before and fanning out all the little hairs, where as before they were kind of shrunk up and stayed on top. Any comments on that?

As for the fish they love the warmer water!! They hang out around the heaters quite a bit and are a lot more active and friendly. They've been eating their fish flakes out of my hand, I'm so excited!!

Oh, we also brought in some new plants but I'm not sure what they are. They started growing in our livestock tanks this Summer while we had the fish out in them. Since the tanks are going to freeze up or be drained, and I wasn't sure my other plants would survive, we brought some of these in and planted them in the gravel bottom. The fish really like them and went crazy over the algae that was growing on them.

Agree with buyorsell. Goldfish like cold water and WH and WL are so cheap you can buy a few plants new each year and they will multiply. Buy only after your pond temperatures are 70 or above for the best results.

HELP HELP .....the leaves are shrivelling. i really want to save this plant. my brother bought these yesterday. its 32 centigrade with 35% humidity they were perfectly fine now they are shrivelled

Water lettuce doing fine, water hyacinth isn't makes me think the goldfish are easting new root growth on the WH. Not uncommon. I'd try moving at least a few WH to their own container to see if that helps.

I've never had a problem with water lettuce and fish, but WH yeah.

my tilapia eat the water lettuce roots, but leave the hyacinth alone; goldfish seem to do just the opposite!
Since I keep the fish in separate tanks, I restock the plants from one to the other.