04 SAN addition to factory ballast

I've been searching forums to see other peoples methods of adding to factory ballast and haven't found what I am thinking so looking for input. My thought is to put sacs on top of my rear tanks and tee into the overflow/vent lines at the top of the tanks to fill into the bottom of sacks. The sacs will be lower than the vents on the sides of the boat so they will fill, then overflow out the vents. When draining the rear tanks, the sacs will drain into the top fittings of the tanks as water is drained from the tanks and eventually empty. Do the integrated bow sac tee'd into the front tank with the similar plumbing. Leave all the factory pumps, valves etc in place as they work fine. The inlets for the pumps are scupper style so the tanks also fill while underway without pumps and remote ball valves can stop unwanted filling when shut off.

Thanks for your comments...

Most guys call it a "piggy back system" and it's pretty common. I did it on my 03 SANTE..You will need to plug the air vent as it's filled because water will drain out as the water level gets higher than the vent. When you empty, watch the piggy back bag because it will collapse causing an air-lock. The air-lock will stop the hard tanks from draining and may cause damage to the gauge sending units. I suggest using the flyhigh wedge bags and quick connects. Do a search on planetnautiqe.

In mine I removed the bunk board on top of the hard tanks. Then placed wedge sacs inside. Re routed overflow to fill spot closest to rear seat. Made a long u shaped hose that is the new vent line attached to top fitting. U need a plug for the overflow or it won't fill the bag. Also, mustnblow water out of u hose to drain. Works very well. Fly high fittings. It's way better with impeller pumps but still works with our aerators. There's a detailed schematic on planetnautique.

Talk to Jason at wakemakers.com. They sell a piggy back kit for your boat and are very knowledgeable about most of the options out there. But I would recommend ripping out the factory system and putting in a fly-high pro bag system (750s in the rear) and seat sac in the locker and adding in either some more aerator pumps or 3 impeller pumps.

Thanks for all the input and I have read quite a few posts now on planetnautique so now my question is, if I tee into the fill line at the top of my rear tanks and from the tee go into the bottom of a sac on top of the tank. The vent lines stay the same and the sac is external to all the flows. After the tank fills, then the bag would fill until it overflows out the vent. If the inlet valves are left open the bag would just drain back into the tank and out the bottom of the boat. If the inlet valves are closed then the sac doesn't drain, and it seem like this set up would work? After the first time, and bleeding the air out of the sac, it seems it would not get much air into it on future fills. The fill line into the sac could droop down and back up into the sac to create a trap to help keep air out of the sac. Any thoughts to this method of plumbing?

Thanks again for the input.

My advice would be to pull the tanks and put 750's in the back. I pulled my back tanks within a week of getting my used boat. That way, you get more storage space when not in use and easier to fill/empty. You can even stick with the aerator pumps, though the impeller pumps are the way to go for ease of use if you have the money to spend the extra $$ on the new pumps. The impellers are super fast but not very easy to use (have to open/close valve, can't empty just one, etc.).

I am now considering pulling my center tank. Anyone pulled their center tank? Do you get extra room to put a bigger sac in on 2002+ SANs?

HSE: that is not how I did it..I went from the hard tank to the bag and out the bag to the vent. You can do the T, but I don't see any advantage. Like I said earlier, you will need to plug that vent anyway if you want to fill the bag above 1/2 way.

Correct Craft changed the ballast system a lot from 1999-2006, so there is a lot of different information out there that applies to different setups.

Because your boat uses aerator pumps it will not work to simply connect a new bag in series with the factory tank by plumbing the overflow into the bag, and then from the bag to the thru-hull on the site. Sure, you can do that, but the fill pump won't generate enough pressure to fill the bag very much, and you'll end up forcing water past the drain pump and out the side of the boat. To actually use the system you'll have to plug the thru-hulls on the side of the boat (as Shooter outlined).

For that reason most of our customers will simply remove the factory tanks to install a larger bag. You get more capacity when the system is full, more storage when the system is empty (because the factory tank takes up the same storage regardless of whether or not it's full), and the system work perfectly, just like the factory setup is.

Short of completely redoing the factory system to install flexible vane impeller pumps (which does not make sense in my opinion), that's your best option for upgrading the capacity of your system for surfing or wakeboarding without creating more problems than you solve.

Our Nautique TankBuster upgrade includes everything you need to make it a plug-and-play swap.

Originally Posted by brhanley

My advice would be to pull the tanks and put 750's in the back. I pulled my back tanks within a week of getting my used boat. That way, you get more storage space when not in use and easier to fill/empty. You can even stick with the aerator pumps, though the impeller pumps are the way to go for ease of use if you have the money to spend the extra $$ on the new pumps. The impellers are super fast but not very easy to use (have to open/close valve, can't empty just one, etc.).

I am now considering pulling my center tank. Anyone pulled their center tank? Do you get extra room to put a bigger sac in on 2002+ SANs?

I think you meant to say "aerators" are super fast but not very easy to use... Impellers are a bit slower (and more difficult to install), but easier to use.

Yes, that is correct, Scott. Aerators = fast, not easy to use; impellers are slow and easier to use. And, for those that already have aerators, impellers can be quite expensive as well. Slip of the keyboard.

Anyone know if I pull that center tank if I would gain any additional room for a bag?

i did the same at BCH. pull the tanks. you will not regret it, i promise. i also installed automatic valves, thus i control all filling and empting from the driver seat to the back lockers.