Outdoor "pond" ecosystem in my horses' water?

[Kelly S]

I'm thinking about options for my horses' 150-gallon water tank. I'm in northeastern Ohio so it doesn't get insanely hot, and I have a drain plug deicer to keep it from freezing. One of my horses is missing all of his front teeth, and another is just a slob, so they're always dropping bits of hay and grass in there. And with the driver, it's even growing algae in the winter! 

That, and scooping it out of my aquariums, got me wondering about putting duckweed in there to use up nutrients and shade out algae. Which of course grew into wondering about putting in other plants and/or a few minnows, in case the plants encourage mosquito breeding. Of course, I will definitely double-check invasive species lists and toxicity before putting anything out there. Has anyone done anything like this?  Any suggestions? Thanks!!

[JettsPapa]

I've kept feeder goldfish in cattle troughs for decades.  I buy the smallest, or maybe the second smallest, they have at the store, and then just leave them alone to eat mosquito larvae, algae, etc.  They'll easily reach 3" - 4" in a few years (excluding tail), and the water stays crystal clear.

For an ordinary sized trough you only need one or two.  I'm in southeast Texas, and don't have de-icers on the troughs since it seldom gets cold enough for them to freeze over, but even when they do the fish are fine below the ice.  They're also okay when the temperature gets well over 100° in summer.

[Dancing Matt]

I have heard white clouds can live under ice. They may be worthwhile if you are interested in something smaller

[gardenman]

You didn't hear this from me (just in case any of my local mosquito control commission are reading this), but letting mosquitos breed in an outdoor water container like a horse trough can give you ready access to live food for your indoor fishes at no cost whatsoever. I'm not saying I do this (don't tell anyone, but I do) but you could use a brine shrimp net and harvest lots of live food for your fishes all spring and summer and even into the fall in my part of the country for free. Local governing bodies (also known as overly officious jerks) don't approve of the practice, but it's been done for decades, often behind closed gates, by tropical fish hobbyists. As long as you harvest the containers regularly they never turn into mosquitos so no harm done. (Though the local officials tend to disagree.) There is the risk of being fined, lectured, harassed about doing it, but it's done a lot. You'll find all kinds of tasty life growing in an open outdoor container that your fish will enjoy chomping down. There will be scuds, daphnia, and mosquito larvae all just sitting there waiting for you to scoop them out and feed them to your fish. 

[Kelly S]

@gardenman I worry that I'd get busy and not harvest enough, but I have thought of trying that in a smaller container that won't torment my horses if my timing is off. I have kept feeder goldfish in horse troughs in the past, but I'm currently more intrigued by the plant idea. I found rosy red minnows recommended elsewhere online, and they don't generate as much waste as goldfish. But the duckweed that is shading my aquariums too much might be helpful shade in the outdoor tank. ? Or maybe some hornwort or something similar to grab up some of the nutrients from hay backwash. I would need to research the others, but duckweed is fine for horses and my chickens LOVE it, so I can definitely harvest extra of that for them.

[Gloryview Farm]

I love this whole idea!  wish I had seen this back when I had sheep here.

[AdamTill]

Goldfish etc in horse troughs is common, but without a filter is not something that’s very kind.

Far more appropriate is just to keep them clean with elbow grease

[Ken]

I never added plants but always had a feeder goldfish or two in my troughs. Where I lived at the time it hit zero degrees fairly often in the winter, I had to break a little ice in the morning even with the heaters going. Cows and horses didn't notice but every now and then I would see a goat giving the goldfish the stink-eye.

[JettsPapa]

5 hours ago, AdamTill said:

Goldfish etc in horse troughs is common, but without a filter is not something that’s very kind.

Far more appropriate is just to keep them clean with elbow grease

I will respectfully disagree.  All my troughs have a float on them, and the animals drink from them multiple times daily, so there's probably at least 50% of the water replaced daily.  The fish are fine without a filter, and it's not unkind at all.

[AdamTill]

12 minutes ago, JettsPapa said:

I will respectfully disagree.  All my troughs have a float on them, and the animals drink from them multiple times daily, so there's probably at least 50% of the water replaced daily.  The fish are fine without a filter, and it's not unkind at all.

When was the last time you checked the water quality? What did it read?

[Daniel]

I bet ya'll are going to me make me lock this perfectly nice thread.

[gardenman]

48 minutes ago, AdamTill said:

When was the last time you checked the water quality? What did it read?

I have a completely unfiltered pond (about 300 gallons) and it's got the best water quality of any of my tanks. The ammonia levels are always zero, the nitrites are zero, and the nitrates are typically at or near zero. Water left outside in a more natural setting tends to take care of itself. It's interesting to watch it. Everything under the sun ends up in there, but the water quality stays pristine. Algae consumes whatever the plants don't eat. I've got goldfish, snails, and God only knows what else living in there, but they all coexist and the pond largely takes care of itself. I have four rain collecting systems (two 30 gallon trash cans and two 110 gallon stock tanks) and all four have pristine water quality. I've tested the water in all four at various times and it's good. Nature tends to find a way to keep things in balance.

[Daniel]

My first reaction to goldfish in an unfiltered cattle trough was sounds good to me. I have got some koi in an unfiltered 7000 gallon pond and they seemed fine.

But then @AdamTill indicated this might not be a good idea. I thought to myself... @AdamTill is a well respected goldfish guy...perhaps I should reconsider?

Some other very reasonable people have had other experiences.

So can we leave it at that?

[AdamTill]

No worries @Daniel, I’m not going to scrap over anything here. I just deal with this a fair amount in the horse world and never thought I’d see it on a fish forum being advocated.

People can handle their animals however they want, but filters of some form seem like a low bar to expect. It’s not like we’re talking Japanese ranchu keepers carefully monitoring their stock in filterless ponds, we’re talking using live fish to prevent mosquitos without really providing for their needs (which can be done pretty easily many other ways).

7000 gals and 150 gals are way different, after all.

If people are keeping 10+ year old goldfish I’ll tip my hat and be quiet, but most people I know are buying fish yearly or every few years. Says a lot for fish that can live decades.

As a horse owner I wouldn’t want then because it makes tank cleaning a pain. Properly scrubbing down troughs prevents vet calls, and having to catch and house fish to properly empty and scrub troughs seems like way more work than needed.

I’ve also run microscopy on too many goldfish to want the parasites they typically carry anywhere near my horses. The probably wouldn’t transfer across species, but I also doubt people are deworming etc their trough fish.

At the bare min, consider using smaller fish with far less waste production. They might not be quite as hardy in all temps is all.

To each their own though, I have no other thoughts on the matter.

 

Edited January 24, 2021 by AdamTill

[JettsPapa]

I also don't want to start a fight, or participate in one.  I am curious about the water parameters in the troughs.  I'll check one later today.

[David Ellsworth]

I just want to contribute, What is a filter? Honestly...It is a section of a system that water flows through to interact with bacteria and filter out particulate. If you have one or two fish in a 150 to 300 gallon or more body of water there is more than enough surface area in that body of water for bacteria to grow on to filter any amount needed. Besides as mentioned with near 50% water added or more daily it is even better than most people's tanks for stocking level and water volume.

 

Every tank has a filter, even the filterless ones. The filterless tanks are just using gravel/sand as the media for bacteria to host and people successfully keep fish with no filter and just substrate. 

[H.K.Luterman]

Just a thought: I believe the whole Walstad method began when Diana Walstad noticed how little healthy ecosystems could be kept in cattle/hoarse troughs and she started her research there. 

[AdamTill]

5 hours ago, David Ellsworth said:

I just want to contribute, What is a filter? Honestly...It is a section of a system that water flows through to interact with bacteria and filter out particulate. If you have one or two fish in a 150 to 300 gallon or more body of water there is more than enough surface area in that body of water for bacteria to grow on to filter any amount needed. Besides as mentioned with near 50% water added or more daily it is even better than most people's tanks for stocking level and water volume.

 

Every tank has a filter, even the filterless ones. The filterless tanks are just using gravel/sand as the media for bacteria to host and people successfully keep fish with no filter and just substrate. 

Stocking levels will have a huge impact on whether things are appropriate.  I’ve had two mature goldfish that required 90% weekly and 10% daily changes to keep water levels appropriate in 75 gallons (defined as no ammonia, nitrite, <40 nitrate)

As for a notion of filters, yes, they’re basically just a means of circulating and aerating water combined with room for beneficial bacteria. Notice that any tub Cory sets up at least has a sponge filter to help move water around though, so we’re at least missing the circulation part.

A stock tank has a lot of area. Any area that’s exposed by water level is out though, and nobody I know adds gravel to the bottom of their trough for the fish. Add in the fact that a trough can heat up fairly warm in the summer and ground water will likely  be 30+F different during fills and you don’t have a particularly stable environment.

In the end though, how long the fish live will be the real determiner of whether I need to reevaluate my thoughts on these setups.

[Daniel]

Good, sounds like although probably no minds have changed (are they ever?), everyone does agree that ultimately the real test is how the experiment develops in the long run.

Ask three fishkeepers a question and you will get five different answers. 🙂

I think the reasonable discussion of differing answers to same question in this thread is not only a testament to the members involved, but also to the kind of environment this forum provides.

 

[ChefConfit]

After reading the original question I think we should look at this more as using an outdoor mini pond as a horse trough rather than just keeping fish in a horse trough because the OP is asking about actually adding plants to the trough. 

So I have a few questions.

Do you have a float to maintain water levels or do you manually fill?

Are you considering a substrate to plant in or only floating plants? 

Would you consider adding an air stone, pump, wave maker of some sort? While not a necessity added water circulation would help keep the ecosystem healthy.

As for stocking I'd suggest white clouds because they are smaller and cold tolerant. You could also go with a small native species depending on your local laws. Maybe some variety of shiner? 

[JettsPapa]

23 hours ago, AdamTill said:

When was the last time you checked the water quality? What did it read?

I checked the smallest tank earlier this afternoon.  It's the smallest of the two I have here at home.  I don't know the number of gallons, but it's an oval shape, 2' deep, 2' wide, and 3' long.  It looks like there might be a little ammonia, but not over 0.25 ppm, which I understand is within the margin of error, and zero nitrites and nitrates (and yes, I shook the bottle #2, and then the vial, like my life depended on it).

I also took a picture of the fish.  The wind was blowing, so it's not a very good one, but hopefully you can get an idea of their wellbeing from it.  The orange one is probably 5" long, excluding tail, and the red and white one about 1" shorter.  I don't know how long they've been in the tank, but it's been several years.  They started as the cheapest, smallest feeder goldfish from one of the pet store chains.  They were at the bottom of the tank when I took the picture, so that should give you some idea of the water clarity, though I know that clarity doesn't always indicate the water quality.

Again, I'm not trying to start or continue a fight, but I was asked for test results.

I hope @Kelly Sdoesn't mind our sidetracking her perfectly nice discussion.

[Kelly S]

This has gotten all kinds of interesting angles since I last logged on! I was looking at minnows instead of goldfish because of size and bioload, but also @ChefConfitis correct that I was also intending to add plants. And I don't see any reason not to quarantine and deworm those fish just like any others. I don't have a firm plan, and I may not do it at all. I manually refill the tank, and while I like the idea of an air stone or sponge filter, those would be plucked out and destroyed by my bad playful geldings. I would be hesitant to use a "normal" substrate because I am well-trained to scrub my tanks, but that does become big water/temperature changes depending on the time of year. Part of the idea behind floating plants was to help keep it a little cooler, but the well water is always going to be colder in summer. Of course, if I were successful in setting up a functioning ecosystem, in theory I shouldn't need to dump and scrub all the time. But I'm not sure I can do that - either piece.  Maybe I'll try just the duckweed to start with and see how it goes. If I lose some when I dump the tank, it's not like it won't replenish itself lol. Or maybe the boys will just play "bobbing for duckweed" until it's gone. The girls will enjoy the peace while they're busy. 😄 Still interested in others' thoughts!