How durable are the show tanks

[Akai-San]

Wondering how durable the portable show tanks are for keeping baby koi? Are there insulated models or systems that can be used in conjunction with over-wintering? Any portable tanks with bottom drains? Hahaha.

[bekko]

Carl,

I have a 10 foot diameter tank which is made of pipe and the same material as the typical show tank. I use it as a spawning tank and for holding fish while I figure out where-the-hell to put them permanently. It has been set up for about two years and seems as good as new. It is in a heavily shaded area under some trees. I do not know what the life expectancy is, but suspect it may be as much as five years. Like most things plastic, direct sunlight and UV radiation do the damage.

They come with side drains. It would be easy enough to put in a bottom drain using a bulkhead fitting and gasket. The ground under the tank can be dish-shaped to some extent to facilitate drainage and cleaning.

I have never heard of trying to insulate one of these things. If you put a piece of 1 to 2-inch thick beadboard (styrofoam sheet) under the tank it will help prevent punctures and reduce a lot of the conductive heat loss. You may be able to wrap the sides with 1-inch beadboard and put a lid on it. Having the water surface freeze could spell death for one of these show tanks as the ice expansion might cut the fabric and it may get very brittle at low temps. Don't really know about that.

Your other alternative may be a more rigid polyethylene tank. The ones here are like huge blue bowls. There is probably something similar in Japan. The cost is not much more than a show tank and they are almost bullet-proof. My wife did an experiment and found that they can fly off the back of a truck onto the highway and hardly get scratched. Again, they come with side drains but can be retrofitted with a bottom drain. A 6 or 8 foot one will fit in a shipping container if you decide to take it with you when you move back home.

Regards,
-steve

[Tom C]

No they do not make a insulated model. I use styrofoam sheets under mine. The thicked the better. Then I wrapped it with insulation and covered it. I didn't have a problem keeping them warm all winter with my heater on it.

[keokoi]

One thing I know with the Pearls tanks are they get a bit brittle if left in sun.. A retro Bottom drain can be fitted as Bekko says..

[Tom C]

I had a Pearls tank up for four year that sat on my patio. Joe is right, they will get a little brittle over time.

[Rich L]

I have a reinforces poly outer for a 12' portable swimming pool. I overlap the ends to act as a form for an 8' tank.



I use 1" foam on the ground and set the form on it. Inside the form I put 1" foam around and inside that, PVC sheet. Whne filled, the PVC pushes the foam to the outer form and I cut the styrofoam to mach the height of the outer form (36"). Two 2" sheets cut to act as a lid finish it.

At one time, I made a 3' high bead filter followed by an 8" dia fluidized bed sand filter that came up through a hole cut in the styrofoam cover. That cut down on my heat loss, but dumping the home made bead filter was a hastle.

I ended up setting the fluidized bed filter in a barrel within the tank to catch the escaping sand (I used play box sand that ran from #30 to #120 in size.) The barrel helped retain the sand so it was easier to remove with a syphon.

[PapaBear]

Clear tanks are great for shows, but not for long term outdoor use as UV will turn them brittle very quickly. Blue lasts longer, but for long term outdoor use black is the only way to go. Carbon black is the primary coloring agent used in virtually all molded plastics and it is nearly UV bulletproof. I have several food grade black tubs that are in direct sunlight summer (90-100degF) and winter (0-30degF) and they show no signs of becoming brittle after several years exposure.