I was really interested to learn that, too. They raise the hardness to grow them from fry, and then let the water get softer as they age. It seems like different breeds of koi develop differently in hard and soft water.
If I had a choice between water lettuce and water hyacinth I would go with hyacinth. It makes a beautiful purple bloom. I think I have a picture of it in my pond pictures album.
I think fret is all our fish know how to do. I'm getting ready to travel overseas for 10 days and the biggest worry on my mind is my goldfish tank.
That's interesting that Japanese breeders have soft water. Hmm . . . that's interesting. All this time I thought my hose water was really hard. Thank goodness Sparky doesn't care what his water is, as long as it's clean. Nice, easy-care Sparky. :D
Hopefully going to get more water hyacinth to help with the nitrates. Oh these fish of ours, how they love to make us fret.
Soft water is anything under 8dGH, so your hose water falls in the category of moderately hard. Maybe show koi need really hard water (to develop certain color patterns), but for pet koi your water is just fine. They just need "not soft" water like goldfish do. With regular water changes to keep the KH up, I don't think you have anything to worry about. Out of curiosity, I went looking into koi and GH (to see if I could find a solid number like for cardinals) and found that a lot of Japanese breeders actually have soft water.
The hose water is KH 8, I believe, and GH 11. It's weird because all the water testing strips say that is very hard and yet a plant book says it's soft. Have you ever heard of using montmorillonite clay to provide minerals for koi? Wondering if I should get some when I order the Koi Kastle from Fosters and Smith.
I'm really glad you aren't in a panic anymore. Ponds can be a lot of fun and scarey at the same time. Glad you were able to get some floating plants! Those should really start to knock out the nitrates once they get going. I've never heard of high nitrates limiting the appetite of a fish, but I do know they are really bad for growing fish.
How hard is the water you have been using? I thought you said the hose water at your house didn't go through a softener? If it's harder than what he recommended, you don't need to worry about the crushed coral. And you can keep on doing massive water changes without a worry.
Oh yes, they are big babies. :D They exist to make me fret. Thanks again Izzy for talking me out of a panic. I did another huge water change today that hopefully brought the nitrates down from 40 so maybe they'll feel better. Seems like the 10 water hyacinth in there are helping with nitrate control.
The koi guy said they should have a KH of 8 and a GH of 16 so I do have a bag of crushed coral in there but he said since it takes time for the coral to dissolve, the big water changes are taking away all the minerals that would make the hardness go up. But if I don't do the water changes, the nitrates go up. So confused.
Sorry it's taking me so long to get back to you (blegh work). I know you're worried about your big babies. With an established pond it would be abnormal for them not wanting to eat, but since you said they can still be shy I don't think it's that abnormal. As I start to feed my guys again in the spring it takes them a few weeks to get used to me feeding them again. Since you haven't been feeding them much maybe they just need to get used to it again. You could always try soaking their food in garlic juice.
Except now the temp's up again. But they still aren't eating. :( How healthy is it for them to not eat when the water temp is about 70-75? I guess I don't have to worry about them outgrowing their pond; they apparently won't eat enough to grow.
Haha, some of the vets probably are. A whole lot of them ended up at one of my local vet clinics, which is nice.
UC Davis is probably one of the best veterinary schools in the country. That and medicine are its main draws for students. The equine vets always accompany the US Olympic Equestrian Team to the Olympics, which is pretty neat.
Checked out the floating plant bags but they're all like 3 feet wide and 2 feet deep or something like that. The koi place has water hyacinth for $1.50 so I figured if they eat them, it's not too much to replace them. Gonna have to order a shelter though, or construct one from river rocks.