DOS AWC

[Jon M.]

So I am setting up my Dos for AWC. I am debating between one 24 hour or several small over each day. Nevermind the pros and cons of the two, I am more concerned right now of the pump failing on and overfilling or draining my tank. I do not have any of the safeguards yet due to funds. Anyone have any experience of these things failing or something blocking the OSW line sucking water out of the tank?

 

[Big G]

Bump

 

[Adalius]

Personally, I'd opt for the small 24 hour changes in terms of failure because:
A) The pump could fail 'on', but it likely won't fail 'faster'. So failing on doesn't hurt anything if you have a 24 hour planned run anyway.
B) Let's say worst case you leave for the day and it fails the second you close the door. If you have it set to do a 10 gallon change in one hour, and it fails on, it's going to be pumping 10 GPH and either dumping that down the drain or into the tank (depending on input or output) for every hour you fail to come home to catch it. If you set it for 10 gallons over a whole day, now it's only pumping about 0.4GPH for every hour you miss it.

So if you are at work for 10 hours and it failed the second you left, the one hour water change has now either emptied your tank or overflowed it, while the other option has only done 4 gallons (neither of which accounts for the addition/removal from the other pump head which presumably would only run for the time it is supposed to).

I'd much rather deal with 4 gallons of water on the floor or 4 extra gallons in the tank (which the sump would probably handle), than an empty tank or 100 gallons of water on the floor, but that's just me.