Question
I live in southeast Texas. I have 2 small red ear sliders that I would like to put outside. I would like to have a koi pond, but would like to make sure that I ma able to maintain one before spending a lot of money. So some one told me that I could get a large 60 or 70 gallon clear plastic storage container, dig a hole and insert it leaving about an inch or 2 of the top still protruding from the ground. I have built a 6x6 area for them to roam around in. I have also closed the top off with some wire to keep predators from them. I have rocks on the sides of the container for them to get in and out of the water. I know this setup is not very extravagant, but as I mentioned earlier, I want to make sure that I can manage an out side koi pond before spending a lot of money. What I was wondering about... is during the winter, would I need a heater or would they be ok without one? Ice normally does not form during winters here, but on occasion it does get really cold. I plan on getting a couple of algae eaters to help keep it clean. I also heard that they need access to the ground in order to lay eggs, so this is another reason why I want to set them up outside. Do you think this is something I should be doing?

Answer
Your 60 gallon pond may be ok for a few small turtles.  It's not large enough for koi.  Koi experts say to have 1000 gallons for the first koi and at least 100 gallons more for each additional koi.  In such a small pond, it would be very hard to maintain water quality with koi and turtles.  Also, with few places to hide, small koi would probably sustain fin damage from the turtles.  

It's important that you completely enclose the turtle pond as you have.  Turtles need access to land to rest, walk, and bask and not just for laying eggs (for females).

If you don't get ice on the pond, then you don't need a heater or de-icer.  The red-eared sliders will hibernate when it's below 55 degrees F or so by sleeping on the bottom of the pond.

There are many animals referred to as algae eaters.  I assume you mean a plecostomus catfish.  They can grow over a foot long if they're the common variety.  They may suck on small fish.  The turtles may try to eat them but they do have armor and could get stuck in their mouths.  Plecos die below 50-55 degrees F and need warm water.  If you need an algae eater, I suggest trapdoor snails.  They are slow to reproduce and won't eat plants.  The turtles may try to eat them too though.

For more on turtle ponds, see my turtle pond page at http://www.fishpondinfo.com/turtles/turpond.htm

I think it would be a good idea to set up a fully enclosed and safe outdoor turtle pond for your turtles especially if it's larger than their current home.  I do NOT suggest adding koi to that size pond especially with the turtles in there.  You might want to add some rosy red minnows.  The turtles will eat them but may leave enough that the minnows can breed and make more.

Good luck!