Plumbing: float switches?

Soon I'm going to be away from home for an extended period due to military deployment. I'm not sure how long, but at least six months and maybe closer to a year. My wife will feed the fish for me during that time, but with two small kids I'm not sure I can count on regular water changes. I'd like to leave at a minimum an automatic top-off system to prevent the pump from cavitating. There should be enough plants to take up nitrate for this period.

The tank is a 75 gallon with 55 gallon sump, unheated.

What I want to do is set up a trash can full of dechlorinated water, with a pump in it, that will turn on when the water level in the sump reaches a certain point, and then turn off before it overflows. All the commercially available float switches I can find are designed for sump pumps to start the pump on a high water level and turn it off at the low level. It seems like it might work to just install the thing upside down, but I haven't been able to look at one out of the box to be sure it would work as I expect. Does anyone have any experience with these, or maybe could suggest a product I've missed? Here's one I'm looking at: http://www.acehardwa...oductId=3706348

There are purpose built units designed for aquaria that you won't need to worry about modifing. Here's one, but you will have to fabricate a bracket.http://www.marinedepot.com/Digital_Aquatics_Float_Switch_Kit_Electric_Powered_Dosing_Pumps_Top_Off_Accessories-Digital_Aquatics-DA1411-FIDPETAC-vi.html

This is just my opinion but I would not trust anything like that for a 6 months - year period without regular inspection by someone. I'm talking about any float switch/automated top-off setup - designed for use in aquaria or not. You could have the wife simply scoop the water from the trash can into the sump on a regular basis, like once a week every Sunday morning or something like that. Good luck with whatever you decide to go with and thanks for serving.

That sounds a bit complicated. I have used a simple livestock float valve that are used to keep livestock water troughs filled to keep and above ground pond and a large fish tank. They are down at our farm and when I set them up in the summer, it may be a week or more between visits so I needed something easy and reliable and something that would work if I am gone awhile or we lost power at the farm and didn't know it.

You can get them at Tractor Supply, mine cost ten bucks and is called the Little Giant trough omatic. The valve has a bracket and attaches and the whole thing fits on and ordinary garden hose. You may need to add a piece of wood to fit it evenly on the top of the tank. The brackets hold the valve so it stays even with the top of the tank. Turn on the water and the tank fills with water, when it reaches the valve there is a plastic float that pushes the valve shut. Whenever the water level drops the valve releases a little bit until the valve is forced shut again by the rising water level.

It is fairly foolproof, does not need power, and only has one moving part. Mine has lasted for years and the water that it releases does not usually need to be treated when it arrives in such a small dose. If your wife wants to do a water change, just turn off the water, syphon out some tank water, turn the water back on and it will re-fill safely without worry or the need for moving buckets. You should use a good hose and you might consider using aquarium sealant glue to seal the end of the hose into the valve housing to make sure it stays secure and water does not leak from the connection. Fairly cheap insurance if you are using it in a house.

Good Luck

That sounds a bit complicated. I have used a simple livestock float valve that are used to keep livestock water troughs filled to keep and above ground pond and a large fish tank. They are down at our farm and when I set them up in the summer, it may be a week or more between visits so I needed something easy and reliable and something that would work if I am gone awhile or we lost power at the farm and didn't know it.

You can get them at Tractor Supply, mine cost ten bucks and is called the Little Giant trough omatic. The valve has a bracket and attaches and the whole thing fits on and ordinary garden hose. You may need to add a piece of wood to fit it evenly on the top of the tank. The brackets hold the valve so it stays even with the top of the tank. Turn on the water and the tank fills with water, when it reaches the valve there is a plastic float that pushes the valve shut. Whenever the water level drops the valve releases a little bit until the valve is forced shut again by the rising water level.

It is fairly foolproof, does not need power, and only has one moving part. Mine has lasted for years and the water that it releases does not usually need to be treated when it arrives in such a small dose. If your wife wants to do a water change, just turn off the water, syphon out some tank water, turn the water back on and it will re-fill safely without worry or the need for moving buckets. You should use a good hose and you might consider using aquarium sealant glue to seal the end of the hose into the valve housing to make sure it stays secure and water does not leak from the connection. Fairly cheap insurance if you are using it in a house.

Good Luck

This is a good way to do this, but if I were doing it in a finished part of a house for long term, I would get a pressure reducing valve from a drip irrigation company, like Dripworks. This will lower your pressure to less than 12 PSI, and will insure that the float valve will not fail. I have had many float valves bleed out water under higher pressures. Not a problem in a pasture, but would suck on your floor.

Part of the problem is that I don't have a hose connection of any kind inside the house. It might be possible to use an elevated reservoir for this sort of setup, but a pump seems less likely to tip over or something, and less problematic by far if it should fail.

I have installed many such systems using an RO unit with an auto shut off to supply water to reservoir which contains a pump controlled by a level switch. Practically de rigeur for a reef tank these days. The worst case scenario thus far has been a failure of the shut off unit, which causes the RO to run constantly. A mechanical float valve in the reservoir prevents it from overflowing, but water runs constantly out of the drain line. Wasteful, but not catastrophic.

If you want to use a reservoir, I would use a demand pump. http://www.freshwate...very-pumps.aspx This type pump will only kick on when it senses a lack of pressure. Then use a float valve in your sump. Use high quality hose, or better yet schedule 40 PVC from the pump to your float valve.

Depending if you rent or own a house, getting a water facuet installed is not very difficult but I would have it done by a real plumber. You might get a plumber to do it for free or discount, if you are going on deployment. They can be installed on just about anywhere where there is a water line. I had one installed in a downstairs bathroom were it was attached to the cold water supply under the bathroom sink. I am too old to move buckets for large tanks, and it was the best investment I ever made for the fish and my back. If the tank is not near a potential faucet spot perhaps it would easier to move the tank to a spot where one can be installed. I also like the suggestion for a pressure reduction valve. Whatever you do the connections have to be secure and all connections can not drip from any spot, even a little bit or you will have real water damage. In your description you describe a sump that must somehow be filled with water, I am assuming buckets being dumped into the can because there is no water point.

Just consider would it be easier to move the tank or move the water point. Perhaps the spot would not be perfect but would work for the year you are away. If the tank could be located were it could be drained to a bathtub, toliet, or even a window then water changes are more likely to happen. My experience is that water changes on large tanks only happen on a regular basis if the water can be drained safely and quickly and the tank filled safely and quickly. That is why I like the livestock float valve when filling a large tank, in case I get distracted or just forget the tank will fill but the valve will shut off the water before it becomes a complete disaster. I forget, everybody forgets, things happen, whatever you decide make sure that is has failsafe has possible.

One other idea, might consider contacting your local fish club, if one exists, and ask if someone would be willing to take in your fish and plants for the year and just shut down the tank. Just one more idea