sump question and premixed water question

[on3ofak1nd]

Ok first of all let me start out by saying that I have a home made sump out of a 30 gallon rubbermaid container with a pump that pushes water through pvc into the tank ( about 4 feet up ) and then pvc pipe siphoning water out into the sump with a power head attached to the end to speed up the gravity siphon. This has worked fairly well for the most part except I have a hard time regulating the water level. It hasnt been too much of a problem except for the fact that I have to keep making adjustments to the inflow valve in order to keep the tank at the level I desire it. Well recently the inevitable happened and I had a small overflow. So for now I've shut down the siphon and I'm running without the sump. So my question is does anyone know of a way I can prevent this from happening or regulate the water level... some sort of valve or switch I could use?

And my second question is, would it be alright to premix salt water for water changes and let it sit for long periods of time before using it? im talking days... I would of course keep it airated with pumps.... Is there anything wrong with this method?

Thanks
-Wes

[yardboy]

You're asking (and getting!) for trouble when you have a pump pulling water out of the tank into a sump and then using another pump to return the water. It'll be impossible to balance over any period of time, as you've found. Build or buy an overflow box so that when the water reaches a predetermined height it overflows into the sump and oversize it (Apparently your need for a pump stemmed from an undersized siphon tube) so it can keep up with the return pump and you'll mostly eliminate your problem. I say mostly because siphons can be lost and clogged, but with reasonable maintenance you should have little trouble.

I don't know if it's wise, but I premix 55 gallons of saltwater and keep it circulating in a container for days, as much as a week before using. I wouldn't use fresh-mixed saltwater anyway. I let it circulate for at least a day before using.

[on3ofak1nd]

Ah I guess an overflow box is the way to go then, Ill search the DIY forum for an overflow box ... or perhaps buy one =)
thanks
-Wes