Fat Sacs with Aerators

[intrlaz]

With no air in the bag, can an aerator pump empty from the top?

[bowvan]

Technically, yes. If there is zero air in the bag and the water level is at the same level as the impeller, you can pump. Keeping the bag free of air in a vented system is near impossible, which is why most empty pumps are located near the bottom of the system. The fittings used to connect the pump to the bag can also create more distance (lift) between the bag and the pump, adding to the problem.

One trick to prime the empty pump (other than pushing the pump down into the bag manually), is to run the fill pump and purge all of the air by filling the system with water, and then immediately run the empty pump.

Another option is to remotely locate the empty pump. The pump doesn't have to be directly attached to the bag. A hose attached to the bottom of the bag and then to the pump will operate the same. The bottom of the bag would be ideal, but the top would also work. Using a hose attached to the top of the bag would work better than mounting the pump directly to the bag, because of the lower profile fittings you could then use.

[intrlaz]

Thanks for the reply. These wont be my permanent sacs that I use jabscos with, but the ones I place on the seats for surfing. I trying to find the best way to manually fill them (with aerator over the side of the boat) and drain without needing to have a bunch of different fittings and without making a mess in the boat.

I was hoping to be able to fill and drain from the same port on the top, and use the other top port to release any air in the sac

[ers906]

That is how I use my wake surf sacs. I usually prime the pump prior to emptying the sac and havent had any problems (maybe a little water let in at the very end but I just dump that over the side). Call up wakemakers, they are extremely knowledgable

[Chexi]

Fly High Pros are great sacs for a plumbed ballast system. However, they do not have a check valve system like the Straight Line sacs do. For this reason, for in-cabin sacs, I prefer straight line sacs with the check valve built into 1 Top valve on the sac. You might get 1-3 drops of water in your boat using this system, as opposed to the potential for quite a bit with the Fly Highs. The fill and empty times are probably a bit longer with the straight line sacs and their line of pumps, but IMHO, it's worth it.

Disclaimer, I have 4 Fly High's plumbed in and only 1 Straight Line for surfing (plus some pop bags) for surfing. If I buy another in cabin sac, it will be a Straight Line / Sumo.

[intrlaz]

I'll let you guys know how mine works out. Im designing it so my port 750 can be removed and filled manually for surfing, and so my port ballast puppy can be used to full starboard side sacks.