I am considering putting a small number of koi in my 1.3 acre pond. Since my visibility gets up to 10+ feet, i think it would be fun to have a few high visibility pets. At the moment my pond has about 330 RBT in the 13-15" range. If the trout don't make it through the summer, I plan to try HSB in this pond next. The pond was finished last fall and has no other fish except some minnows that already existed in the spring that fuels the pond.

My question is this: how likely is it that the trout or HSB will basically eliminate the koi yoy? My hope is I can stock larger koi and not have any meaningful survival of the offspring. Do you think it would matter if there were HSB or RBT as the primary occupant?

What do you think?

Several things will contribute to recruitment of koi/carp. I may not deal with all of them.
1. Amount of good spawning habitat. The better the type and more quantity of shallow shoreline or shallow structure for egg attachment the more eggs will hatch. Shallow grassy, weedy areas prime spawning habitat. Just about any firm underwater surface will hold carp eggs.
2. Amount of cover for fry fingerlings. This is pretty self explanatory.
3. Food for carp fry is normally not a limiting factor in a pond like yours. Food source should be ample for good carp fry survival. Fry are planktivorus.
4. Your pond has very few predators present of hatched carp fry until they are bigger than 1+". Survival to 1"+ should be very good.
5. HSB and IMO trout tend to be more open water predators. I welcome other opinions on preferred habitat of RBT or HSB. Small carp (1"-5") will be bottom oriented due to feeding habits. YOur predators and prey do not have behavior habits that cause a high amount of interaction thus IMO this will lead to high survival rates of fingerling carp.
6. Adult mature koi are sexually dimorphic (adult males and females with external recognizable features). A single sex koi population is possible and suggested.

Thanks Bill. I had considered a single sex option, but was deterred when learned that breeders charge up to $100 to sex a single fish. From your comments, I seem to hear that sexing of fully mature carp is reasonably doable. Given the relatively low recruitment of carp in more common mixed ponds, I thought predation might be effective.

Now, I'm thinking I should grow them out, sex them, and then select individuals for the pond. I have a small RAC system that might work for this.

I am will Bill... I would highly recommend you stick with single sex koi. If you had a healthy LMB population in your pond, I would be less concerned. Plus your pond is just so unique, I'd hate to see a bunch of koi making a mess of it!

If the RBT are surviving in the pond long enough for you, and you want some color swimming around in the pond, have you looked into the golden color morph of the rainbow?

I would not mix koi with trout ever. First those koi are going to be trout food no matter where you put them if they are not big enough. The trout will get them in the shallows, wherever they go. Then, when the koi do survive, they will eventually take over pond, make clear water very turbid. Trout just can't handle turbid water long term. I'd go with the gold bows if I wanted color. Koi go in koi ponds, trout go in trout ponds. There is not a koi/trout pond. Almost can't be long term, they are not compatible.

Would the Koi even spawn in the trout pond if the water was kept cold enough for the trout? It'd be a moot point if the water warmed up over 70° tho.

Koi will spawn with temps in the high 60's.

Carp were spawning like crazy this past week at Raystown Lake where the water temp was between 64-68 in the shallows.

Thanks for the comments. From what I have read, the koi would spawn. If I could get golden, tiger or brook trout, I would go that route, but I have not been able to find a source. I really have a hard time imagining a small number of any fish dramatically affecting my visibility; the entire issue is whether recruitment can be prevented.

All species of fish have a certain range of temps they thrive at. And die at. Or practically go dormant. When trout are thriving, carp are dormant, when carp are thriving, trout are dying.

Here is a simple question for the entire forum, in all of thier years observing ponds, has anyone ever seen a successful trout/koi pond? Ever?

What is the optimum temp for a trout pond?

What is the optimum temp for a koi carp pond?

My reference listed optimum koi temps as 65-75. Acceptable koi temps range from about 35-85. RBT need to remain below 70. They prefer about 60. My pond will be in the 60s much of the summer. I am still waiting to see what temperatures max out at in late summer.

Koi need to be in water above 74 F for thier immune systems to actually work properly. Medicines and treatments for any problems do not work at 65 F. Digestion completely stops at 45-50 F. If they eat and have food in thier digestive system it will rot and they will die. Koi thrive in water temps above 75 F.

Trout thrive in cold water. The colder the better, down to 40 F. When they are thriving, koi cannot do anything but lay there dormant. When Koi Carp are thriving, Trout are floating belly up, dead. This is not a it depends subject.

We have tons of carp here in the Great Sacandaga Lake and I see them spawning in the shallows of an inlet near my house, If the difference between koi and Carp is nil then there seems like there would be a good chance they would survive in a cool water pond but maybe not spawn.
If Brkt will survive in your pond they would be less likely to decimate small Koi but Brnt and especially tigers would murder your Koi. Then as mentioned would Koi roil up the pond to the detriment of the trout.

MoMule, If your just looking to add a few Koi for fun I would say go for it, if their large enough the trout won't bother them and a few shouldn't affect the pond.
If you go with single sex that would eliminate problems down the road, and half the fun of having a pond is experimenting.

This place ships tiger trout, maybe if you had a cage to raise the fingerlings might be worth checking into.
http://www.coldspringstroutfarm.com/pond_stocking.htm

Let me know the water temp you decide on for both species to remain healthy.

Next up, ice fishing for tilipia.

Interesting reading.

http://www.pondtrademag.com/articles/ar-73/

I doubt koi would "thrive" in a trout pond... However, koi/carp are hardy little buggers and I think the koi would manage maintain. Their growth rates would be greatly reduced though and perhaps some increased risk of disease. The one trout stream I fish supports both wild naturally reproducing populations of brown and rainbow trout. I regularly see and occasionally catch carp in this stream. A stream that stays cool enough to support trout year round but also supports carp and some darn big ones at that...

I may not succeed, but I don't see any real problem giving the single-sex option a try. I think my boys will love them. I may be surprised, but I have seen carp survive in much harsher consitions than this pond would seem to pose. I think I will grow them out in my RAC until they can be sexed. Then, all of one sex will go to the trout pond. Honestly, I'm much more confident about the koi than the trout.

I'd go with all males if possible... That way if you goof, and throw in a female their reproductive ability is limited.

Good idea on the males. Thanks for the constructive help.

What medicines or other treatments would you expect to be delivering to KOI that are in a large trout pond? I'd expect that would never be an issue?
You'd have a bigger problem of the turbidity of KOI waters affecting the trout negatively then you would with temperatures as long as you stay in a safe range for the type of trout. Koi can survive an incredible temperature range so the odds of killing them off with temp variations that trout would survive would be limited at best.

I dunno TPF but I'd say everything is an 'it depends subject'. If the OP just wants both species to survive and can provide a middling temp with enough D.O. then it is entirely doable. Optimum for both, not likely, but that is the case in almost all bodies of water/species combos. Of course the thermocline in a pond will in theory allow the fish to sit at their most desired available temp.

I have koi & trout (among other fish) in my pond and don't seem to have a problem with it. I've had more problems with the bluegill in my pond but I think that was from too many mature bluegill and not enough spawning area and it stressed them. The koi and trout both seem happy, grow well, and feed together during feeding time.

Great read AP. Guy brings up some interesting points. Out here we have nothing like that as far as Winter temps yet almost all of th edie offs and crashes are in the Winter. And he hits the nail on the head with lack of O2. A lot of the novice koi owners think you only need a Spring cleaning. More important is a preWinter cleaning. All that vegetative matter just sucks up or removes the O2. How many posts do we see here on this forum about Northerners having die off in the Winter with any species?

Plus with Koi, he says you have to due several things, limit the desirable population, cull all diseased fish. Provide non stop O2/aeration even before the pond ices over. This is just not feasible in a large trout/koi pond.

As far as koi diseases, and why they kill them off in the Winter. The immune systems just start shutting down below 70. Digestion stops at 50. They are dormant, or clinging on to life, waiting it out. If they are weak, diseased, parasites, over overpopulated they just don't make it through the Winter. I don't have the space to list all of the diseases and parasites these fish can get or have. I think fungus is the number one killer though. And again, you just can't treat that in cold water, the medicines won't work. There are even procedures on how to raise water temps to treat koi with medicines.

There is no happy medium for these two species to coexist. There is no water temp for both of them to thrive. Koi can withstand very cold water temps, but only for thier Winter cycle. As soon as you heat them up to get them fat and happy your trout are dead.

Would be nice to see some photos of this. What are your seasonal water temps? And I have seen bg happily coexist with both trout and koi. Especially trout. Even gsf. We have a winery that has a trout/bg pond they hand feed all season long and then lets kids fish for the trout in the Spring. I think it is called Indian Rock. Usually the biggest is around 10 lbs, but this year it was only 9. There are no koi in there, and never will be. But plenty of trout and bg. Too many mature bluegill and not enough spawning areas so they got stressed? You have many firsts my freind, never heard of anything like that either.

As far as seasonal temps, it goes from iced over all winter to about 72 in the middle of the summer. 72 was the peak last summer and it lasted about a week. This spring it climbed to 60 but has dropped back down to 52 as of yesterday because of the cold weather we have been having.

The too many mature bluegill and not enough spawning area was suggested to me on this site. After it was all said and done last year, I believe that theory was correct.

I'll work on getting some pictures of the koi and trout together this weekend.

2trackin, it sounds like you have a great little pond, I like to see people doing things with their pond that is out of the ordinary.
What is your ponds water source and what species of trout do you have?

Photo's would be great.

You have trout that lasted 72F for a week? Amazing! I have a pond that all the trout die in one day with 70 F. Customer knows this and we are working on a solution to recirc the water and shade it. Also might try a different variety, but getting fish into Cal is getting tough.

BG are prolific spawners, and I cannot fathom how would they stress not having nests, let alone how they could not make nests. I had a pond with 3 feet of muck and just two adults and it was loaded with babies. I have another pond now where the bg are practically the last fish standing after a die off. I am sorry, but I am not buying the stress thoery.

Temperature isn't the only factor in rainbow trout surviving. Water temps could be 60 degrees but the rainbow trout would die at a DO level of 2 ppm. Water temps could be 75 degrees and rainbow trout could survive a week if the DO level was 10 ppm. DO is just as if not more important than water temp.

My pond is heavily aerated with a solar aerator. I know trout will bite the big one fast with O2, but I was under the impression right around 70F is the cutoff as far as temps, even short term like a week. That what the trout experts tell me at least. The longer they go at 70 and above the weaker they get until floating.

When he said his temp. got to 72 I'll bet that was taken at a 2 or 3 ft. depth so he probably had 65 in deeper water.
I have my temp probe in 5ft. of water so I can better judge any problems that might happen in the summer, it's never gotten above 68 probably due to the 95 gpm inflow.

In flow, a spring, anything with cool O2 water is huge. The trout actually seek that out and stay there. My problem is none of the above, plus literally zero shade. One little foot bridge and that is where they all hang out until floating. Also the naturals or regulars are much more heat tolerant vs. the triploids, which is what we want. So I'm thinking better off just getting them to live than watching triploids float since they are not as hardy. I just got a load of dregs, bullfrog polliwogs/res/gsf and bg. Probably 120 lbs. Have to get busy sorting.

I know this picture means nothing. I took about 30 pictures tonight and those trout are just too fast. So, I ended up with some koi and a trout splash. I'm still going to work on better pictures this weekend.

AP,

My pond is a water table pond, I live across the street from a lake that they control the lake level with a pump. I think that has some influence on my pond as well although it still does go up and down. The trout I have are golden rainbows. I like brighter colored fish because my pond is pretty tannic.

I'm surprised that the pond stays cool enough, the ground water or springs must be supplying enough cool water.
Between golden rainbows and Koi you really need to watch out for Herons.
Some floating islands would give your trout more shade when it's hot and it seems most pond life enjoy what they provide.

Great news 2trackin! I couldn't really believe this hadn't been tried. In my setting I have a spring-fed waterfall dumping 300-2000+ gpm. I think this will really help with DO and creating a cool flow area for the trout. I wouldn't be surpassed or unhappy if the koi seek out other warmer parts of the pond.

2trackin-- do your koi successfully reproduce to maturity or do the trout and other fish eat off the young?

koi and golden rainbows=easy targets for ospreys

In the winter, the side of the pond facing the woods is always the last to freeze and first to thaw (even though its always shaded), so I may be getting a little spring water, I'm not really sure though.

I've had koi for 3 years now, last summer was when I put the trout in and I did it as an experiment. I only put 20 in as a test to see if they would live. As far as I can tell, the only one I lost was the one I caught ice fishing and it went in the fry pan

In my area, last summer seemed to have a lot of cooler than normal nights. I'm sure that contributed to my success. Who knows what will happen this summer? We may get some hot weather and I'll have to turn the kids loose with the fishing poles to get them out.

I like the idea of floating islands, I've checked out a lot of photos of them on this site and would like to make one.

Now, if someone can just breed some cool water tilapia to eat my dang duckweed, I'll be all set!

Well, it took a while but I finally got a good pic. Here are some koi & golden rainbow trout enjoying feeding time together!

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Cool pictures! I've checked more koi references and they seem pretty consistent that the upper end of trout temps are very acceptable for summer high temps.

Well, my pond has been warmer this year than the last few. It was bouncing between 72 at night and 74 during the day for 3 weeks. One day it spiked to 75 for around 6 hours. The last couple of cool nights now have it 70-71. I would have never thought the trout would have made it through these temps but here they are yesterday chowing down with the kio & bluegills. as far as I can tell, I haven't lost a fish yet.

Rainbow trout are much hardier than people give them credit for with plenty of DO.

DO is most important for trout. I have fished lakes that were cold enough for trout and people would catch an occasional trout but a lack of good DO at cooler water temps hinder the trout and prevent them surviving the summer

Well, my surface water temperatures were way above the 70 degree temp that RBT are suppose to want. But, they nonetheless MADE IT THROUGH THE SUMMER. In cas your wondering, I am pumped. I have zero doubt that koi would survive the temperatures in my pond.

Great news MoMule!!! Maybe you'll get really lucky and They'll pull off a spawn near the cave entrance....We STLL need some pics of your new ponds!

Very exciting they survived...