3/4" vs. 1" Ballast Hose/Fittings. Did I make the right choice?

I opted to go with the 800 GPH Tsunami pumps and 3/4" hose, flow rite fittings, and check valves. Fill/drain times faster than 15 minutes are of little benefit for my application. If we flip the switches as soon as the hull hits the water launching, parking the truck & trailer, idling through the no wake zone, waiting for the first rider to get ready, etc. there's simply no way all of that could happen at my normal spot in less than 15 minutes.

Based on a few tests that I saw on different forums I estimate that my longest fill time will be in the neighborhood of 12-13 minutes with 800 GPH pumps and 3/4" hose. I will be using 3 fill pumps (One per bag) and 4 drain pumps for a pair of 750s and an integrated bow sac (dual drain pumps).

It would have been over $150 more on an already expensive project to go to the Tsunami 1200s or Rule 1100 pumps and 1" hose, fittings etc. and made things a bit more complicated on the plumbing due to extra adapters and what not being needed.

I received everything and everything just looks really small in diameter. I measured the ID of the Tsunami 800 pumps and it's the same as all of the fittings (~1/2") and what not but it just seems wrong. I guess I'm used to seeing the 1 1/8" hose and fittings on my portable pump.

I guess I'm still at a point where I could return the stuff and go to 1" but has anyone else gone with the Tsunami 800s and 3/4" hose and gotten acceptable performance out of it?

Thanks,
Jeff

You setup will work fine. As you noted, fast fill time is not a priority. That real restriction is in the 3/4 male sac valve thread fitting. Ive tested the T800 with 3/4 and 1" hose using the 1" fittings and there was not a huge difference. The real slow down didnt come until I retested using the 3/4 sac valve fittings.

I wasn't really considering using the 800 GPH pumps with 1". If I went with 1" I would have used pumps that would have taken more advantage of it (Tsunami 1200 or Rule 1100).

I guess I was really just surprised at the 1/2-19/32" ID of pretty much all of the fittings (Flow rite, check valves and even the output of the pump itself). I had seen ballast systems plumbed with 3/4" hose but at a glance you don't really see the ID of any of the fittings. It logically makes sense that the walls would be in the 3/32-1/8" range eating up 1/4" of the hose diameter but I just hadn't thought of that beforehand. The plastic 3/4" thru hulls and Ys that I got for the drain/vents are the smallest ID of all of the fittings at 1/2" ID. The Flow Rite fittings are the largest diameter at 19/32" ID.


I'm wondering if I should have gone for the vented loops on the rear bags instead of the check valves because that's just one more restriction since I have to route the hose above filled bag height anyway. I figure a 2' tall loop of hose with a check valve is probably more restrictive than a 2' tall vented loop with no check valve. I might have to test that theory. My assumption is that the vented loops aren't very restrictive on their own and it's just the additional "head" on the pump that causes restriction. For the bow sac the check valve is probably my best option since I don't need the same tall loop in the fill line anyway (Bag isn't as tall and is higher above the water line).

Another area that I was thinking about that seems really restrictive is the 90 degree elbows that come off of the Tsunami 800 pumps. I'd think a straight fitting would probably work fine for most of my pump spots. FlowRite makes a straight female 3/4" NPS fitting that's supposed to work on the Tsunami 800 but I didn't order any of those so I'd have to pay a lot of shipping relative to the cost of the 7 fittings.

Also it looks like StraightLine/SumoSac is putting a 1" NPT fitting on their bags now. I wonder if FlyHigh/Barefoot Intl./Fat Sac will step theres up. That seems like it would make the faster pumps much more effective and worthwhile since you could potentially avoid any fitting with an ID of less than 3/4"

Did some quick but semi-scientific testing, some math and it looks like the 3/4" Bosworth check valve from WakeMakers reduces flow by around 8.1% (.35 GPM in my test) and the Flow Rite 3/4" 90 reduces flow by about 5.5% (.24 GPM in my test).

Not sure how multiple flow rite 90s would affect flow but I would imagine that each additional one wouldn't have the same 5.5% reduction given that a lot of the "damage" is done by the first one and any subsequent 90s would likely have a smaller negative affect.

My methodology included a coiled 65' piece of 3/4" ballast hose. I know it's long and restrictive but I didn't want to cut off a piece before I laid out my system and end up not having enough and having a piece that was too short for any application. I used the same hose for every test and I figure it may have improved accuracy and consistency because it increased the duration of each test which should minimize any stop watch errors. I had a 30" head from the position of the pump in the source bucket to the highest point in the hose leading to the destination 5 gallon bucket. The source bucket was a 2 gallon with a garden hose feeding it. The pump kept about a 3/4 pace with the hose at full blast so I had to back the hose flow off a bit to avoid the source bucket overflowing constantly. I "primed" the 65' hose to make sure that each test was on an even playing field. The pump was powered by a 12 volt UPS battery that was connected to a 2 amp charge throughout the test. I got super consistent results doing each test 2-3 times. The mosquitos were vicious so when I got towards the end if I got the same result twice I moved on. With just the hose it was 1:08 each time to fill the 5 gallon bucket to the point of overflowing. With the check valve it was 1:14 and with the 90 it was 1:12.

Not sure how these results would translate to other configurations like shorter hose length, smaller or larger head, multiple fittings, etc. but it does make me feel a little better about the affect of the 1/2" ID fittings because they seem not to have a huge effect on the flow. I probably should repeat the test with both the 90 and the check valve on the hose.

I should also mention that in addition to the obscenely long hose length reducing the speed this battery+charger was only putting out about 12.4 volts and Attwood rates these pumps a decent amount higher at the typical 13.X volts that a boat with the engine running would provide.

I hate to make you second guess, but I just did what you did with the 3/4 hose and 700gph pumps last year. This year I just spent 400 to upgrade everything to 1100s and 1" hose. I switch it up for surfing and we have nearly no wait to get where we are going. I wanted it to be faster than it was. I was filling a 750 sac in about 15 minutes before. I havent got the boat wet yet this year to see the difference.

I don't surf but mainly because I haven't had sufficient ballast in the past. I might try it here and there after the ballast system is in but quick regular to goofy changes aren't really a concern.

My plan if I ever did need rapid surf stance switch capabilities was to just put a Simer reversible pump (Not in the bilge since they aren't ignition protected) that teed into a hose going from one sac's drain hose to the other. Then I could pump from one bag to the other while simultaneously filling the bag from the aerator pump. Being that there's no "head" and it's just moving water horizontally it should get pretty fast speed compared to drawing water in from the bottom especially since I could be filling with the 800 GPH aerator at the same time. Once I was about 1/2 way through the switch I'd flip the empty pump on the source side on to start emptying the remainder. I'd imagine this setup would give me the ability to switch stances in 5-7 minutes or less.

I did a full scale test a couple of nights ago with a 750 lb sac on my porch and a 5 gallon bucket on the ground 15" below. The hose went up to a 30" height before coming back down to the bag. With the 800 GPH pump I used 5 ft. of 3/4" hose with a 3/4" Bosworth check valve, a Flow Rite 90, and the 3/4" flow Rite to Fly High adapter. Fill time was 11 minutes. I'm pretty happy with that so I will be proceeding with the 3/4" install.

I am not an expert in fluid dynamics; however, it would seem to me that a diameter constriction (say down to 1/2") will do most of its flow rate damage once (i.e,. if you have 3 1/2" bottlenecks, the effect is not cumulative). However, if you have 3 90 degree bends, the effect is cumulative (although perhaps not perfectly additive). A 90 bend adds turbulence, which will slow the flow rate down. Just because you got turbulence at one point, doesn't mean you won't get it at another point. You will, and it will slow flow rates. Another thing to consider is that it would seem to me that all pumps' flow rates are inversely proportional to the size of the ballast bag (i.e., the bigger the ballast bag, the slower the flow rate). This is because as a bag fills, the back pressure increases. The bigger the bag, the more back pressure there will be (as it fills). A 3/4 full 750 sac should have more back pressure than a 3/4 full 400 lb sac. Finally, it would seem to me that aerator pumps are more susceptible to these declining flow rates than impeller based pumps because there is no seal and back pressure can push water back even while filling. I believe this is the reason why aerator pumps have higher theoretical flow ratings but impeller pumps fill often just as fast or faster. Neither pump style should suffer from this on emptying, so aerator pumps should beat impeller pumps on emptying.

Note, the back pressure issue should not be a factor if the pump intake is located on the top of the bag, which may be how aerator systems are designed (although with most Fly High bags, there is often only 1 fitting at the top of the bag, and that is reserved for venting). Impeller-based systems are built with intake/outflow at the bottom of the bags, so back pressure is a factor, but as I stated above, less so than would be the case for aerator pumps.

This all my non-scientific thoughts. I know that I could fill a 400 in 3:30 seconds with a Johnson Ultra Ballast impeller pump. I would expect that to be closer to 10 minutes on a 750.

Most of the Fly High bags have 2 fittings on top and only one on the bottom. My 750s are definitely like this as well as all of the other V-Drive type sacs. So, with an aerator system you fill from the top, drain from the bottom. It doesn't start "pushing back" on the pump until the sac gets to the point that it's stretching and wants to spurt water out of the top which is really only for about the last 15-30 seconds of filling. Until you get to that point the pump hums along at a consistent pace then it sounds like it's loading up as it attempts to "inflate" the bag with more water. Depending on the space that you have the bag in you may not even get to that "inflating" stage before the compartment is completely full though.

I just ordered some of these from Flow-Rite:
https://www.flow-rite.com/product/ad...ht-pipe-thread

That will eliminate that first 90 coming off of the Tsunami 800 pumps which I think will help the flow out by a decent amount. That way the only 90s I will have will be where the fill lines connect to the bags. I could eliminate those too in favor of a sweeping bend in the hose but I think it would end up kinking or, at a minimum, applying more stress to the fitting on the bag.

One more thing that I noticed about the Tsunami orientation. It had a huge effect on flow. Their documentation doesn't really mention it but the pictures always show the pumps oriented horizontally with the output (Without the elbow) pointed straight up.

I found that these orientations seemed to work well:
Vertically with the intake down
Horizontally with the output pointed up (As shown in the pics in the instrcutions)
Horizontally with the output on the bottom (Pointed to the left as you're looking at the cartridge top)

Obviously upside down would be bad so I didn't try that but horizontally with the output on top (Pointed to the right as you're looking at the cartridge top) surprisingly worked really poorly. I tried it two different times and it reduced flow by 50%+.

Now this is some useful information.