Finally going for auto ballast. Fed up of hoses!

I have finally ordered a through hull fitting, some valves and another pump to fill my fat seat and front sac.

Got fed up of throwing hoses and pumps over the side and messing about.

I've only got a fat seat in the rear and a 400lb sac in the front so just got a 1" scupper and ball vale with a 1100gph aerator and t'ing off this to font and rear sacs.

Question is if on the rear fat seat i try to run the fill and drain aerators off the same fill line (eg try and pump water back out my scupper) will I encounter problems of the water just going full cicle and hitting the T piece and going back into the seat?

You could use check valves so the water would only flow one way. I'd recomend getting a throughull for your drain above the waterline though. Its alot faster that way.

The water will flow to least resistance, so you'll just keep filling your fat seat. Do as Don says and get a thru hull for above the water line to drain.

Are you draining from the top or bottom of the bag? It makes a difference for burping.

draining from the bottom. I'll just get an extra outlet to drin at the rear then.

Since you are draining at a bottom port, you'll need to get rid of any trapped air within the bag.

If you have an extra port on top of the bag you can just run that to a above the water thru hull or use the drain thru hull with a check valve.

If you don't have an extra port, make your fill hose go above the highest point of the bag. At that point, 'T' off the hose and run the one end out a thru hull or connect to the drain line via a check valve. The 'T' must also be below the thru hull.

Hope this helps and makes sense.

is there any safe way to add a port to fat sac?

Justyn, yes there is. Use a 3/4" plastic thru-hull fitting. Attwood makes a good one for about $3. Cut a 3/4" diameter hole in the sac and then stretch it around the flange of the thru hull. Then screw the nut down tight and attach your hose. Use teflon tape on the threads and a little silicone at the hole to seal it up good.

There was a pic of this in another post from the past. May have been on wakeboarder.com if you can't find it here.