Choosing koi types based on your ponds water and qualities??

[Brutuscz]

I have been catching my koi to prepare them for the pioneer valley show. As I am catching and asessing each one...I am evaluating my ponds qualities and effects. I am finding that several kohaku have developed shimi's. Two of my 3 kujaku have turned very dark. A platinum ogon has developed shimi's. An asagi has developed a dark gray head. Now, the odd thing is that my water is very soft. TDS-50, GH-40-60, KH-20-40. But...The pond is a black liner and in direct sunlight.
In contrast to this, My shiro utsuri look awesome. Bekko, Kumonryu, matsubawake..most kawaragoi are looking great. Showa look very nice. Even sanke look good.
Basically...if sumi is involved, the koi look great. If it is a koi that I don't want to get dark...too bad!!!
I may start trying to make purchases based on this. Stick with the varieties that look outstanding...and forsake the ones that will not improve in my pond. Stop wasting space on kohaku that will go nowhere, and enjoy my shiro utsuri, kumonryu and showa!!!
Do any other koi keepers and competitors on this board do this?? What varieties work for you?

[hwong]

I dont analyse my pond water for the parameters that you do but I have the same problem with shimis on some of my Kokakus (even the quality ones) but not all. I guess it depends on the parents; some Kohakus are bred with sankes in their lines.

Sumis are superb in my pond and I have refrained from added anymore Kohaku, now and in the future.

[koiczar]

Brutuscz

I installed a water softener and still don't have the water parameters you have (Gh,Kh). But, what is your Ph? That might tell the story, I'm not sure. I do know that I no longer get shimis and the Maruyama Kohaku that DID have one, lost it within a month of firing up the softener.

I do still like to find fish that do well in my water parameters. This makes good sense. It takes a while but seems to pay off in the end. I just purchased 8 showas, from various top line breeders to see/observe how they change/develop after 2 years in my ponds (QT for at least 6 months in 1250gal tank) then MAYBE to main pond if they show potential. The rest will be give aways to other club members who aren't so fussy. I also have a few Sanke going through the same routine. We'll see what happens in a year!?

Mike

[PapaBear]

I remember thinking to myself when your big move provided soft water that you'd have the opposite results you report. Our kh is around 100-150, gh 200-250, ph stable at around 7.8 and the only Kohaku with shimi's is one that had is before it came to our pond. The other has never had any and the beni and shiroji both remain soft and clean. Sumi friendly seems to be the rule of the day when it comes to shiro's as our growout fish is doing great, as are several bekko, so it does make me wonder a bit about the relationships. What seems most effected in our water is ogons of any color.

[JasPR]

although there is fundamental truth to the almost urban legend at this point, that hard water brings out sumi, this has been given way too much blame/credit over the years.

It is as much about placing a fish that has been raised in a mud pond into a closed system ( especially in concrete or in liners with high nitrates) that is responsible for rapid finish. And that is what you see when you see showa getting black or shiro utsuri becoming more defined. Put another way, hard water does not make fish have MORE sumi. That is a function of genetics. It makes a fish express it's genetics more rapidly when compared to a mub pond setting.
I imagine that you see shimmies on kohaku due to two factors:

1) genetics ( 75% of the results we see are down to good genetics and bad genetics

2) change of water parameters- crowding leading high nitrogenous waste species, pH, water minerals/hardness ( 25%)

When fish 'finish', there skin is actually aging or maturing. Some fish finish rapidly due to genetics. Others age prematurely due to environment. And within premature aging are 'tricks of the trade'. Just as you can force a fish to grow faster than normal, you can cause a fish to finish faster than normal. You may want to do that on purpose or you might want to try and hold that off, depending on the genetic potential of an individual fish.
JR

[Brutuscz]

Here are some pics I took to show the story. The kohaku is from BWcreek. The pics are over a 2year span. There are no shimis in the first 2pics..but in the recent picture, 2 large shimis.
The kumonryu is from last season to this season. The shiro utsuri is over 2 years. The kujaku is just over a few months last season...I sold this one. But..look how it changed so rapidly. I currently have 2 others that have dome the same thing...only worse. Really Dark!!!

The kohaku really shocked me. This one won it's class at a show 2yrs ago. I caught it to enter it again...and the shimis really were unexpected. Not sure what to do long term about this?? Give up on kohaku and focus on showa and SU...or make some type of changes to my water? Any advice is appreciated!!

[Lam Nguyen]

Herein lies another limitation of this hobby in that an average hobbyist is limited to the type of koi that s/he can keep in the pond. From looking at the pictures of the koi that you posted, it looks like your water is very conducive to sumi development. From what I have gathered, sumi development is based on (1) high pH and (2) very hard water. You said that your water is very soft (TDS = 50; GH = 40-60; KH = 20-40). How about your pH?

My pond is very good for beni development (pH = 6.8-7.2; GH - 60-80; KH = 60-80). I had several kohakus from SFF & Hoshikin and none of them developed shimmies during the past two years. On the other hand, I had a couple of Omosako shiros for about 1.5yrs and the sumi developed very slowly. As a result, I am starting to collect more kohakus than sanke & showa. IMO, I think that your pond is very good for koi with sumi.

[farne230]

Interesting topic. This year for the first time one of my kohaku has developed what some think is underlying hi development after almost four years. My water parameters are high PH (8.2 to 8.6), GH at 72ppm, KH at 200, TDS at 300, Temp at 80's. first picture is before shin discolor between first and second step. Remaining photo's note red discolor. What do you think, water chemistry, infection, temperture, food (hi-silk 21)?
Bob

[PapaBear]

Just to toss another curveball into the mix, it has been my understanding that high hardness levels impact has more to do with aging/finishing/hardening the finish, rather like a "fixative".
The direct relationship to Sumi development as I understand it is more related to the specific levels of silicates in the water rather than hardness in general. More "urban legend" stuff, or rooted in fact?

[MikeM]

The Japanese Inland Fisheries guys did studies 20 or so years ago identifying silica as the mineral needed for sumi development. Silica is omnipresent, but higher in sandy areas. Going back to the early days of koi breeding, the breeders observed that the best sumi came from certain ponds, which often were in areas of higher sand content to the soil. Silicon levels in water tend to rise and fall with general hardness. It does not have to be correlated, but generally is.