Already have tanks under the seats putting V drive sacs in locker just want to make sure this is how? I will use my existing pumps not worried about fill time, it will give us time to chill and have a beer.

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NO BEER<img src="http://www.wakeworld.com/MB/Discus/clipart/proud.gif" border=0>

don't you want to fill the bag from the tank vent? So that when the tank overflows, it does so into the sack.

I agree with shawndoggy. 2nd, I dont see how the tank will drain as it looks like water is traveling "up hill" from the factory tank to the sac and the drain pump is on the sac.

So go Vent on the tank to fill on the sack and then vent the sack.

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<a href="http://i709.photobucket.com/albums/ww100/walker44/BALLASTINSTALL.jpg" target="_blank">http://i709.photobucket.com/albums/ww100/walker44/BALLASTINSTALL.jpg</a> <BR> <BR>This is how I did my piggyback. Hard tank vent to bag- Bag to outside vent line. The bag will fill and drain through the hard tank vent line. The bag drain pump may work better when draining, but I didnt go that route and I have not had any issues. <BR> <BR>You just need to plug the outside vent when full and watch for airlock when draining. There is a lot of information out there on this subject. <BR> <BR>(Message edited by shooter_08 on January 14, 2010)

I will ad a may fair pump to drain the tank in the 2nd picture.

^^^Yep!

Exactly. ^^^^ <BR> <BR>Water goes into the factory tank, then instead of overflowing back to the lake(your factory vent hole) you divert that to your fatsac intake. Once the fatsac is full, you then run a hose from the vent hole of the sac to the factory vent thru hull to go into the lake. <BR> <BR>You could then add an additional pump to drain out the h20 from the sac and out another thru hull, but you can also let it drain back into the factory tank and out through the factory drain. All you need to do is plug the 3rd hole on the sac and as the factory tank drains (from the bottom of the tank obviously), the water from the sac drains into the tank and out that way. A little slower but it works well. I do this on my wakesetter and it works awesome, took maybe 15 minutes, and drains all but a gallon or two out of the sacs. I have them on quick disconnects so if I know I am not using the boat for a week or so I take the sacs out, drain the last couple gallons manually and let the compartment air out a little bit.

<a href="http://www.themalibucrew.com/forums/index.php?app=core&amp;module=attach&amp;section=a ttach&amp;attach_rel_module=post&amp;attach_id=132 21" target="_blank">http://www.themalibucrew.com/forums/index.php?app=core&amp;module=attach&amp;section=a ttach&amp;attach_rel_module=post&amp;attach_id=132 21</a> <BR> <BR>As others have noted need to drain the tank...

Stuey, your way assumes that the bag is above the tank, right? So that the bag gravity-drains into the tank which then pumps out via the factory pump? OP doesn't say, but if his tanks are not below the bags, I don't think your way would work, would it?

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The tank will be the same height as the bag.

Yes shawn that is correct... however i'm sure it wouldn't have to be exactly top and bottom to drain back into the lower bag. But you are right, it wouldnt really work if the length was too long. <BR> <BR>The weight and force of the water coming out the 'lower' opening on the bag would put some pressure on that line, letting it travel back to the tank. For instance my sac fittings are farther back than my actual tank so the water travels thru maybe 18" of line back into the factory tank. Which is probably why I get a gallon or two leftover. I'm sure if it was a shorter line and directly on top it would be a little better.