My water hyacinth have turned a rather sickly looking yellowish. Never had this happen before. Pond tests out perfect-0 ammonia, 0 nitrite, 0-10 nitrate, 7.4ish pH. Fish are happy and healthy. Filter is running and maintained as normal. Nights have been cold, in the 40's. Cold is my only guess. Any ideas?
off-color hyacinth
I would guess cold too. Other years, I have gotten my hyacinths way too early, and they have done very poorly. This year, I got them later, and they are doing well. I also have started to add potash and iron to my pond 1 or 2 times a week, and that has helped my plants not to turn yellow. I have read of others taking their hyacinths out of the pond and soaking in a pail of water and miracle grow for a day. Then rinse them off and throw back in the pond. I haven't done this myself.
My hyacinths are in full sun all the time, and this year are doing well, with the additives I give to the pond. That's all I have changed this year, so might be something to it.
Glenda