Dual livewell circulation problem

TheMan90241 · 05-01-2008, 06:51 AM

I have a front and rear livewell system that I have been working on and I am trying to get all the bugs out. Both livewells fill properly. The forward livewell will not stay full. When circulating fresh water in, it drains at an equal rate, thus never filling completely to the proper level. I think I can fix this problem by adding a standpipe forcing the well to reach a determined level before draining through the standpipe. My problem is the rear livewell. It does have a standpipe, but will not drain. The drain tube is clear of any obstructions from the standpipe all the way to the bilge exit hole. I think what is happening is this. When the livewell is filled, the water level of the well is equal to the outside water line. Because there is no elevation in the livewell, the water does not flow out (unless we are under way). So, when I keep the intake pump on to circulate fresh water, the rear livewell overflows. Has anyone had a similar problem and how did you fix it? Thanks, Terry G.

tykim717 · 05-01-2008, 07:32 AM

i'm no expert but it sounds like the exit hole needs to be lower. are there bends in your exit line? especially bending upwards. if so there may not be sufficient head being produced by the water mass in the tank to cause the drain water to travel through the exit hose and out the bilge exit hole. may want to look at installing another pump in the drain line. does you tank fill from the bottom and exit from the top or the opposite?

**Carnivore** · 05-01-2008, 08:27 AM

What boat ya have? year make model etc. Search for specific info on-line about it an see if others have the same problem. I know in my boat it has a center box that some use as a fish box but I found out you have to have a macerator pump to clean the box out that my boat didn't come with. You might need to have a pump that will pump water out when you are sitting still or have to remove the limit pipe till your underway.

TheMan90241 · 05-01-2008, 08:27 AM

There are no bends in the line. It fills from a sprayer at the top of the tank and emptys through the standpipe that is about 2/3 the total hight of the tank. I added an image to the original post do ilustrate the drainage issue I'm having. It does empty when I'm under way because the boat rides higher on the water and the forward movement causes the water to exit to the rear. The whole configuration is very frustrating.

tykim717 · 05-01-2008, 04:50 PM

yup...you'll need a pump with that kind of setup.

ironman · 05-01-2008, 05:44 PM

it has livewells in the front hu do you have pump outs in the back also post a pic of the livewells and the conrtole panel what happens to is it will only drain as low as the water and it will never pump all the way out unless your livewell plugs are in hope that helps

marineslayer · 05-01-2008, 06:26 PM

Having both tanks drains tied together with the t is the big problem here,viva the bottom of the forward tank is higher than the top of your back tank,unless you have a check valve on your back tank? and the drain on the aft tank should be at the top and the inlet at the bottom,thus elimanating the need for a stand pipe for drainage, which looks like its at the water line. separate drains,poke thru hull for fwd. tank,looks like short run. I have 2 sizes of stand pipes for my fwd. bait tank,cause if its rough sometimes it splashs out under seat,and squid stay fine in half a tank,turns it over faster. Just my thoughts though,hope it helps you out.

TheMan90241 · 05-01-2008, 09:49 PM

Maybe I should put this thread on hold for now until I get some good photos. I will be removing the gas tank and replacing the two cable control valves in two weeks. At that time, I will take photos and draw a new diagram to show all the water lines, pumps, wells, drains, and recirculation lines. Thanks for the help for now. Until then, I will disable the rear livewell and only use the forward one. I know I can at least get that one to recirculate and drain at all times. I will update the thread in a couple weeks. Thanks again.

**Carnivore** · 05-01-2008, 10:07 PM

I buddy of mine a few years ago had kind of this same problem when (large) people were in the rear of the boat. How we solved it was to put a pump in the rear tank with a bilge pump float at the lever he wanted it to stay at. When it got high it would turn on automatically but underway it wouldn't come on. It's a thought if not a good one.

dragonfeathers · 05-06-2008, 03:09 PM

It kinda looks like your rear tank is under the waterline??? If so the pump might be the way to go. However, two things to consider.First being having one line for the two to drain out will cause problems if one is higher than the other. The higher one will prevent flow from the lower one if the pipe is anywhere near full. Therefore a seperate throughhull drain might rectify this problem.Secondly, flow of the tanks are measured in "time to fill tank" not gallons per minute. A good rule of thumb for timing tanks is 7 to 11 minutes to fill the tank to the top of standpipe.If you only have one pump filling both tanks, a baffle system is required to adjust the flow.Very important if the tanks are not the same size.
Having said all that though, if the back tank is below the waterline and the overflow is
trying to push uphill..... go with the pump
Mike