Custom ballast system question

[Fman]

Fman
my 3 1200 tsunami fill a 400lb bag in 7 min+ I do have 3 intakes. I thought that it will be a faster fill. It looks like the single 1" scupper will do the same job. I just though that to pull that much water to fill all 3 sacks just might not work. I stand corrected.

400 lbs is about 48 gallons of water. Are you talking about (3) 400 lb bags? Because a 1200 Tsunami is rated for 20 GPM, which would would fill a 400 lb bag in about 2.5 minutes. I believe you did the right thing by having a seperate intake for each pump. You can only get about 38-40GPM max out of one 3/4"-1" scupper.

I am currently using (3) 800's off of one manifold and one intake. I can fill 1900 lbs in about 9 minutes. I was considering trying the 1200's to speed this up, was not sure if the 1200's are actually producing 20 GPM fill times. I am getting about 25-28 GPM with three 800 Tsunamis, not too bad but would be nice to get a little more flow with the 1200's. 1900 lbs of water is about 228 gallons of water.

I dont know why Atwood did not make the 1200 more user friendly with standard NPT 1" or 3/4" thread. From what people are saying its a pain to adapt the 1200's to 3/4" NPT.

Did you have any problems?

[jasonwm]

There's some good info in this thread, but also some inaccuracies.

Just to clear this up for anyone one else that stumbles upon this thread, please do not use a scupper intake for your ballast system. There is essentially no benefit to using a scoop type intake, and if you use aerator pumps you will be forced to include some type of ball valve (manual or electronic) to prevent the flow of water into the bags when running at speed.

Impeller (Jabsco Ballast Puppy or Johnson Ultra Ballast) and Aerator (Rule, Attwood, etc.) pumps both have their advantages and disadvantages, the key is to design a system correctly for the type of pump that you'll be using. If you do that, then the functionality and speed will be perfectly acceptable.

A good example of this is the MLS system in Malibus and the new Gravity system in Supra/Moomba. Malibu uses aerator pumps while United Marine uses impeller pumps, but at the end of the day, both systems work very well and are quick to fill and drain.