keeping an outdoor darkroom water tank from freezing?

I've got a question for those of you with outdoor structures for darkrooms who use an outdoor tank for water supply. I think at least Sean and one or two others fall into this category.

Since I've decided to go with a standalone structure in the backyard instead of converting my garage for my next darkroom, I've also been thinking lately that a 200Gal tank would be a great idea for water supply instead of running plumbing from the house. I'd fill it periodically with the garden hose, plus I imagine that it could also collect a bit of rainwater as well. Since I'll be using a two-stage filter system for the water in darkroom, I figure the pollutants in the rainwater (or tap water for that matter) shouldn't be too much of an issue. As a side thought, I figure this tank would also make a good source of emergency water, if needed.

What do do in the winter, though? How do those of you with outdoor tanks keep them from freezing in the winter? Heating it with a submersible element doesn't seem like a great idea... Since I'll be wanting to keep a minimum of heating running in the room even when it's not in use, I thought maybe I'd vent the outgoing air from the vent hoods around or even up against the tank to recycle some of that heat.

What do you guys do?

-KwM-

Here you'd watch it freeze -). Bury it? Put it deep enough and it won't freeze.

But I'm betting your weather is warmer then my winter. How about a smal solar panel hooked up to a heating element. Insulate the tank well and that might be enough to avoid freezing. 200 gallons is a big tank.

Kevin:

How far away is your darkroom from the nearest faucet?

David

Does it get that cold in Texas? I would pick up a stock tank blanket and wrap it, these are available at most ranch stores, that is what alot of the horse ranchers do around here in the winter to keep water available for their horses, and it gets to about 40 below at times during the winter around here.

Dave

KW,

Design for the tank to be inside and over head in your structure, or enclose and insulate enclosure.....put it high enough so you have gravity pull at all levels, you can put in some light bulb sockets in the enclosure housing the water tank....turn them on at night or wrap the tank in an electric blanket....if this solution is not possible for you just add a suitable amount of cheap vodka to the water

Dave

Satinsnow said:

Does it get that cold in Texas? I would pick up a stock tank blanket and wrap it, these are available at most ranch stores, that is what alot of the horse ranchers do around here in the winter to keep water available for their horses, and it gets to about 40 below at times during the winter around here.

Dave

Click to expand...

Hey Dave, that sounds pretty cool. Maybe I'll combine that idea with my other one and vent the darkroom through an enclosure around the tank, and insulate the enclosure.

It doesn't get all that cold. Maybe a couple of days a year go below zero, if that. We might have a week or two in a row where the temperature consistently dips below freezing at night. If a tank wrap does the trick for ranchers wher eit gtse 40 below, maybe the enclosure is totally unnecessary... Hrm.

-KwM-

David Brown said:

Kevin:

How far away is your darkroom from the nearest faucet?

David

Click to expand...

Dave,

I figure about a hundred feet, but I haven't broken ground yet. Just accumulating ideas for design at this point. Maybe I'll break ground in a month or so. fingers crossed.

-KwM-

You might try a submersible heater for stock tanks (for cattle)--most have a built-in thermostat and come in a variety of sizes. I have one for a 100 gallon of so tank, that keeps it thawed in -20F weather. It cost less than $100.

Dave Wooten said:

KW,

Design for the tank to be inside and over head in your structure, or enclose and insulate enclosure.....put it high enough so you have gravity pull at all levels, you can put in some light bulb sockets in the enclosure housing the water tank....turn them on at night or wrap the tank in an electric blanket....if this solution is not possible for you just add a suitable amount of cheap vodka to the water

Dave

Click to expand...

wow. Today's my day for getting Darkroom design help from folks named Dave.

Good point about the gravity feed, Dave. Overhead'd make me too nervous. Looks like an outdoor tank'll have to be up on a platform at least 50-60inches high, since I figure I'll place the bottom of my sinks at about 37" and put the supply plumbing on plywood mounted behind each sink on the studs.

-KwM-

Two ideas:

First, heat the tank during the day with sunlight, by enclosing it in a cheap plastic greenhouse. I have seen inflatible models with no solid struts needed. Also look into plastic sheets of bubblewrap-like material designed for sun-heating swimming pools and retaining the heat at night.

Second theory, supply the shed with running water by burying a black plastic hose, like those used to water lawns. Puting it down a foot or two will usually prevent freezing. Irrigation firms have machines which will feed the hose without digging a trench.

Actually, the more I think about it, you don't need to heat or insulate the tank (although insulation wouldn't hurt). If the water would freeze, it would freeze on the perimeter first, leaving the interior fluid. In Texas, I don't think it would ever freeze solid. So just heat or insulate the line from the tank to the darkroom.

I know it sounds unconventional, but if you built the tank on the roof of the darkroom, the roof top, which is usually warm, would keep the tank bottom warm. And the supply line would be enclosed and probably never freeze.