Vanishing Sumi

[dizzyfish]

I have several Showa and one Shiro Utsuri that have lost much of their sumi.
They are in a large 27,000-gallon liner pond. I just checked the water parameters. Nitrate: 0 Nitrite: 0 Total Hardness: 150 Total Alkalinity: 120
PH: 8.2-8.4. I run a UV and two large bio bead filters, but the water is still a little dirty and has some foam. The pond gets a brutal amount of full sunlight here in the Kentucky summers. (Read: About 11-hours a day)

I read in Mamoru Kodama's book Kokugo (Perhaps Vol. II) that too much sunlight can cause sumi to fade. I haven't been giving the koi any clay. Anyway here are a couple of before and after photos. Does anyone have any ideas as to what is going on?
Thanks,
Mitch

[Sangreaal]

What is the temperature of the water, the oxygen content and the size of your koi, Dizzy?

Marie

[dizzyfish]

Marie,
The temp is currently 72F but the sumi loss began at higher temps, perhaps around 82F. I don't know the exact O2 content, but the pond is turned over about every 3-hours and has a large waterfall. The largest koi are around 24" and there are 3-4 this size. I have several (maybe 25) in 18-21" size. I probably have 100 koi total not counting this year's fry.(200) Several of the other koi are in the 6-10" range. I'm going to seine out most of the babies in a week or so and move the best ones inside to a large swimming pool. Not all of my Shiro Utsuri or Showa have had their sumi to fade. I have quite a few koi in a fairly large pond, but it doesn't appear to be way overcrowed at the moment. I do plan on thinning because I would love to grow out some jumbo koi ASAP.
Mitch

[MikeM]

Dizzy: I do not know what is happening, but I'll start a listing of possibilities for others to chime in. (1) Sumi can fade in high temperatures and consolidate in lower temperatures. This is less likely with high quality, mature sumi... more likely with low quality or immature sumi. (2) Baby sumi on young utsuri group fish often fades revealing more white or red, but can come back as the fish matures. This is most likely in tosai and less developed nisai. (3)I have read articles which suggest that high nitrate levels can interfere with Sumi development. You list zero nitrate. That seems unlikely unless you are doing continual in-flow of nitrate-free fresh water at a high rate. (4) Older koi in the utsuri group can have the sumi break apart and decline. Poor conditions can prematurely age the fish... high temperature, low oxygen, high nitrate, ammonia, etc. (5)Sumi develops best in high silica water, which is generally harder water. Yours is moderately hard. I think it sufficient for good sumi development, but theoretically there could be a deficiency in silica. This is pretty unlikely, I think.

So, there are 5 thoughts to ponder. Maybe DickB can contribute. He has a lot of first hand experience watching sumi develop.

[dick benbow]

Mike, I think you've done an excellent job of going thru the possibilities by the numbers....what bothers me is the foam mentioned....means there's decomposing organics which do rob oxygen. There is no mention of water change, once a water gets depleted of minerals there is nothing for the koi to extract and that goes for the filter bacteria as well. I think declorinated trickle
of 24/7 might be in order here. Might be a good idea to get an area shaded with some shade cloth to get them a place to get out of the sun......as the temps cool for winter we'll find out if the black is back but in the meantime let's get a continual 10% water change going......

[dizzyfish]

Mike and Dick,
I want to thank both of you for your replys. Mike I rechecked the nitrate this morning using the Jungle Quick /Dip strip. You are right in that it is not zero, but probably more in the 10-15ppm range. It is definitely under 20ppm if the test strips are to be believed. I had used the Jungle 5 in 1 test kit last night, and read it a little hastily. Dick I don't like the foam at all, but feel like the water fall contributes some. I'm using two 1/3 horse Lim Dragon pumps in conjunction with two Wave Model 60 Pressurized Pre-Filter Settlement tanks. I also have a large 8' long x 36" deep x 30" wide filter brush/ settling filter with a bottom drain down a steep hill. Inside the box I have two complete rows of 6" diameter x 36" filter brushes, so a double row of brushes run the entire 8'. One of the 1/3 horse pumps feeds out the back side of the filter brush tank near the bottom. Those pumps are rated at 6426 GPH and I ran 3" PVC up to the waterfall, and I also used large sweeping 90 degree schedule 80 electrical conduit to reduce head. I used one 3" pvc line for each system and the height I had to pump too is 7' above the pump height. So in short I don't know the exact head, but I feel like I'm moving quite a bit of water down my waterfall. I also use and 1800 GPH pump to feed my 40Watt UV which is a seperate system. I am toying with the idea of adding some type of protein skimmer in the filter box area.

Now a word about water changes. I do lose a little water via the waterfall or whatever, but it is probably more in the 1% range. I change roughly 25% of the water twice a month. By my calculations to change 10% daily in that pond would require 81,000 gallons of water per month. It would be something on the order of filling up 3 fairly large swimming pools per month. I got a water bill earlier in the summer. It was $100.00 for water and $200.00 for sewer. Well it cost me a grand but I had a second water meter installed that feeds my outside hydrants only. The last water bill was $100 for the outside water and no sewer charged. The inside water meter was $8 counting water and sewer. I'm a backsliding tree hugger at best, but 81K gallons of water for the one pond makes me feel a mite too wasteful. And that's not to mention the energy consumption to run three pumps and a UV. When you factor in how quickly my herd can go through an 11# bag of food it gets pretty pricey. All things considered having a large pond is for people who have the green, not for those who want to live green.

I'll say I agree that shading the pond would help, but I'm trying to keep it as natural looking as possible. I have planted a couple blue Atlas cedars and also two deodar cedars which will provide eventual relief from the brutal sun, but also falling needles and such. I guess I'll figure out a temporary way to provide shade. I want to build a bridge, but I have a 20' span to cross.

I got out my copy of "Kokugyo" by Mamoru Kodama out last night. It really is a most excellent book. Anyway FWIW I'm going to parrot a small quote from Mr. Kodama on page 89 under a section on Karasugoi. He writes "Because Sumi is a protective coloring, Sumi becomes lighter when we put Koi in a bright pond or pool. The Sumi of Karasugoi will never get lighter, regardless of the surrondings."

Thanks again,
Mitch

[KoiCop]

nice pond, nice fish.

A couple things:

1. No self-respecting koi hobbyist should be testing with dip strips; please invest in a decent test kit.

2. It doesn't matter how good your filtration system is if the water doesn't flow through it frequently enough -- and your 3 hour turnover rate is marginal, at best. Please increase the flow to the 1 to 2 hour level; every 30 minutes would be optimum.

3. It's nice that you have a big pond and lots of koi, but if you don't 'flush' the toilet enough, the waste builds up; that's why you have foam and are starting to see conditioning problems with your koi. You need to either drastically reduce your koi load or drastically increase your water changes -- and I'd recommend both. I would consider 7% to 10% per day as a good rule of thumb.

4. As for the cost? Koi keeping is not cheap. And like that Fram filter commercial, you can either pay for it up front or pay for not doing it correctly later on. Your choice, Mitch.

Best wishes,

[koiczar]

Quote: Originally Posted by dizzyfish Mike and Dick, I want to thank both of you for your replys. Mike I rechecked the nitrate this morning using the Jungle Quick /Dip strip. You are right in that it is not zero, but probably more in the 10-15ppm range. It is definitely under 20ppm if the test strips are to be believed. I had used the Jungle 5 in 1 test kit last night, and read it a little hastily. Dick I don't like the foam at all, but feel like the water fall contributes some. I'm using two 1/3 horse Lim Dragon pumps in conjunction with two Wave Model 60 Pressurized Pre-Filter Settlement tanks. I also have a large 8' long x 36" deep x 30" wide filter brush/ settling filter with a bottom drain down a steep hill. Inside the box I have two complete rows of 6" diameter x 36" filter brushes, so a double row of brushes run the entire 8'. One of the 1/3 horse pumps feeds out the back side of the filter brush tank near the bottom. Those pumps are rated at 6426 GPH and I ran 3" PVC up to the waterfall, and I also used large sweeping 90 degree schedule 80 electrical conduit to reduce head. I used one 3" pvc line for each system and the height I had to pump too is 7' above the pump height. So in short I don't know the exact head, but I feel like I'm moving quite a bit of water down my waterfall. I also use and 1800 GPH pump to feed my 40Watt UV which is a seperate system. I am toying with the idea of adding some type of protein skimmer in the filter box area. Now a word about water changes. I do lose a little water via the waterfall or whatever, but it is probably more in the 1% range. I change roughly 25% of the water twice a month. By my calculations to change 10% daily in that pond would require 81,000 gallons of water per month. It would be something on the order of filling up 3 fairly large swimming pools per month. I got a water bill earlier in the summer. It was $100.00 for water and $200.00 for sewer. Well it cost me a grand but I had a second water meter installed that feeds my outside hydrants only. The last water bill was $100 for the outside water and no sewer charged. The inside water meter was $8 counting water and sewer. I'm a backsliding tree hugger at best, but 81K gallons of water for the one pond makes me feel a mite too wasteful. And that's not to mention the energy consumption to run three pumps and a UV. When you factor in how quickly my herd can go through an 11# bag of food it gets pretty pricey. All things considered having a large pond is for people who have the green, not for those who want to live green. I'll say I agree that shading the pond would help, but I'm trying to keep it as natural looking as possible. I have planted a couple blue Atlas cedars and also two deodar cedars which will provide eventual relief from the brutal sun, but also falling needles and such. I guess I'll figure out a temporary way to provide shade. I want to build a bridge, but I have a 20' span to cross. I got out my copy of "Kokugyo" by Mamoru Kodama out last night. It really is a most excellent book. Anyway FWIW I'm going to parrot a small quote from Mr. Kodama on page 89 under a section on Karasugoi. He writes "Because Sumi is a protective coloring, Sumi becomes lighter when we put Koi in a bright pond or pool. The Sumi of Karasugoi will never get lighter, regardless of the surrondings." Thanks again, Mitch

Mitch

Your concern about losing the sumi is good but I think you misunderstood Kodama's statement. "Sumi becomes lighter in a brighter pond..." What I believe he's eluding to is that if your pond walls and bottom are of a light color, say white or blue plaster, then yes, the sumi will tend to lighten up. Also, you only mention your Nitrate level readings. How about your GH readings? Also, how old are these specific fish you're concerned with? How much have the actually grown over this summer season?

I agee in part with KoiCop concerning your turnover rate. I know that's a big pond but it is important to move the volume of the pond through the filters a little faster. I would say 1.5 to 2 hours would be fine for that size system.

I was at the Sacramento Koi Show this past weekend and Toshio Sakai was the head judge and gave a very good lecture. At the banquet on Saturday night, he spoke about the GC and the RGC and how water quality and seasonal feeding affects the fish. He said that during the summer months, say, July through September, he feed high protein food (silk worm) and increases the oxygen level up to 4 times normal. He stated that you shouldn't be able to see your fish clearly through the air being pumped. I really believe this helps your filtration system run more efficiently at a time when overfeeding/overcrowding becomes more of an issue. The air diffusers are bringing the water from the bottom of the pond up to the surface and allowing proper degassing of the heavier gasses. It also circulates the water much more than any circulation jets can provide versus the cost factor. So, bigger bang for the buck!!

I also agree that reducing your stocking density can only help. 100 fish is way too many! If you cut it in half you'd be way ahead of the game.

Now, you mention that you're using two Wave Dragon 1/3hp pumps. Did you know that the manufacture does NOT recommend using 3" pipe with this size pump? He clearly states in the instruction manual that for best efficiency, 2 1/2" is the best. Using 3" actually reduces the efficiency of the total head. So, you're actually not getting the most out of those pumps. Good luck with your endeavors. I don't think the sun is the total problem here. It may be a contributing factor but not as important as correct water quality.

Mike

[dizzyfish]

Quote: Originally Posted by koiczar Now, you mention that you're using two Wave Dragon 1/3hp pumps. Did you know that the manufacture does NOT recommend using 3" pipe with this size pump? He clearly states in the instruction manual that for best efficiency, 2 1/2" is the best. Using 3" actually reduces the efficiency of the total head. So, you're actually not getting the most out of those pumps. Mike

Mike, I appreciate the advice and realize I need to change a few things to optimize my system. The stocking rate is certainly one thing. I just lifted this from www.wLimcorp.com under the page for Dragon pumps. (which included the 1/3 hp)

"The pumps come with 21/2" unions for IN and OUT. A 2 1/2" pipe will give you higher pressure, but the flow will slightly decrease.You must increase to 3" pipe to get 100% max flow. This will not over amp the motor; and will match the performance curve we have provided."

I think I decided to go with the 3" pipe after reading that on the site, but don't exactly recall now. Elliot recommened the pump size and the filters based on the information and pictures I provided him. It may be stated different in the instruction manuals, but I thought less friction=greater efficiency, but I'm a far cry from a plumbing engineer.
Mitch

[koiczar]

Quote: Originally Posted by dizzyfish Mike, I appreciate the advice and realize I need to change a few things to optimize my system. The stocking rate is certainly one thing. I just lifted this from www.wLimcorp.com under the page for Dragon pumps. (which included the 1/3 hp) "The pumps come with 21/2" unions for IN and OUT. A 2 1/2" pipe will give you higher pressure, but the flow will slightly decrease.You must increase to 3" pipe to get 100% max flow. This will not over amp the motor; and will match the performance curve we have provided." I think I decided to go with the 3" pipe after reading that on the site, but don't exactly recall now. Elliot recommened the pump size and the filters based on the information and pictures I provided him. It may be stated different in the instruction manuals, but I thought less friction=greater efficiency, but I'm a far cry from a plumbing engineer. Mitch

Mitch

Okay, that's different than what he used to say. My pump is now 4 years old and came with 2" unions. I guess it's one of those situations like with Jandy valves - the unions are 2"female or 2 1/2" male - your choice!! You are correct about friction loss being a factor - usually - however you can oversize your pipe and lose flow as the weight of the water traveling through the pipe increases causing an extra burden on the pump to "push" the extra weight. At least that's what I've understood from an explanation given to me by an engineer.

Mike