Livewell Plans for 175

[CTsalt12]

Hi All,

I'm in the process of plumbing a livewell on my 175, and I was hoping I could get some input from the Classic aquasport faithful to validate what I'm doing so I don't screw it up.  I'm repurposing the port stern hatch (included on 175s from 1989 onwards) as a livewell.  It has a 5+gallon capacity, and while the shape isn't perfect I think with a 110 GPH pump It should hold 3 adult menhaden for me, and a bunch of the little 'peanut' size.   I have attached a sketch of my design, and some pics of the hatch and parts. 

A few questions have come to mind:

1. Strainer before pump, after seacock shutoff valve.  correct?
2. Drain hose towards the bottom, so I'm able to drain just about all the water.  To route it over the side of the boat the hose will have to go up from the point where it meets the well.  Will the force of gravity on the water be enough to push water up and out?
3. Fill hose at top of tank, so freshwater comes in the top, old water goes out the bottom.
3. Livewell lists 5AMP fuse needed.  I've got a fuse on my switch panel, any reason this wouldn't be sufficient?

Anything I am missing?

[Capt. Bob]

Hi All,

I'm in the process of plumbing a livewell on my 175, and I was hoping I could get some input from the Classic aquasport faithful to validate what I'm doing so I don't screw it up.  I'm repurposing the port stern hatch (included on 175s from 1989 onwards) as a livewell.  It has a 5+gallon capacity, and while the shape isn't perfect I think with a 110 GPH pump It should hold 3 adult menhaden for me, and a bunch of the little 'peanut' size.   I have attached a sketch of my design, and some pics of the hatch and parts. 

A few questions have come to mind:

1. Strainer before pump, after seacock shutoff valve.  correct?
2. Drain hose towards the bottom, so I'm able to drain just about all the water.  To route it over the side of the boat the hose will have to go up from the point where it meets the well.  Will the force of gravity on the water be enough to push water up and out?
3. Fill hose at top of tank, so freshwater comes in the top, old water goes out the bottom.
3. Livewell lists 5AMP fuse needed.  I've got a fuse on my switch panel, any reason this wouldn't be sufficient?

Anything I am missing?

1. Correct.
2. No sure what you are asking. As shown, it will allow the water to circulate if the the drain hose diameter is big enough to discharge water equal to what your pump is supplying. Usually, the overflow pipe is large and plumbed at the spot where you want the highest level in the tank. If you are referring to draining the tank at the end of the day then... No, not as shown. As per your drawing, the water level in the well will remain at the same level as the invert (inside bottom) of the drain pipe. Easiest method is to drain the well onto the deck and out the scupper.
3. That would work hydraulically if the water level in the tank is higher than the surrounding water (ocean/bay/river).
4. No, just as long as you size the fuse accordingly.

Good luck.

[CTsalt12]

Thanks Bob.  That is good to know that the drain diameter must be wider or equal to the inflow diameter..   

What I was trying to say with point #2 is that the drain hose in my design would be a few inches from the bottom of the well.  However, the hose would be directed upwards to get the water over the sides of the gunnel. I’m wondering if the water will in fact go up and over or if the gravitational force won’t be enough to do that, and the water won’t drain at all or fast enough. 

Should I instead use  both a drain hose at the bottom of the tank  and an overflow hose at top of tank?  I see some designs use both.  I’d like to have a steady flow of fresh water in, and water out, while keeping the water level constant and the well full when the pump is on.  Hope this clarifies. 

[Capt. Bob]

CT,
Concerning #2, the water in the tank will only drain out to a point that is the same elevation of your drain. The lower your drain exit pipe, the lower the water level will become when you open the drain. If you placed the drain exit higher than the level in the well, no water would drain so....

Assuming the well will be placed on the deck and that the deck is a couple of inches higher than the outside water level, you could exit the drain at or below the waterline. The water in the well would then be displaced (by gravity) to the outside. CCPs used this method to drain the deck but when the outside water level became higher than the deck drain (think steep ramp launches or several weight challenged fishing buddies) water flowed back onto the deck.

I drain my well onto the deck itself and out the stern scuppers (via attached hose). My well also has the "overflow" drain located at the upper level of the well. That seems to be a standard setup on deck mounted wells. Built-in wells often use an "overflow tube" that is placed in the drain hole at the bottom of the well. This allows just one opening in the well for both overflow while in operation and drainage (by removing the tube) when done. Again, the well drain itself is above the outside waterline.

Good luck.

[CTsalt12]

Got it, thanks Bob.  Overflow drain over the transom in addition to a 'exit' drain that will go to the deck it is. 

[CTsalt12]

Attaching an updated diagram of my livewell plans based on input from the CAS gang (thanks Cap Bobb). 

Got a couple outstanding questions I'm hoping you can help with.

1. I'd like to have my pump mounted to the bottom of the livewell, a couple feet up from the strainer/seacock.  Any issue with this and the pumping power to bring water up?
2. I understand the pump is not bidirectional.  Water can't go back in the pump and out my thru-hull.  Correct?  In diagram #2 I'm thinking I could use a T fitting to send overflow water back out the thru hull.  Instead of over the back of the transom.  Would this work?  Assuming that if the pump was on in this scenario, it would bring in water from overflow and new water from thru hull which could be an issue...

[boatnamesue]

Couple potential pitfalls here, depending on your answers.  Outflow is passive...as water is pumped into well, water passively flows out.  If your outflow hose exits the well then immediately goes vertical, the water will not drain properly.  And unless the top of your well will be sealed, water will take path of least resistance by dumping out of the top.

Which brings me to next potential pitfall...how do you intend to seal the top of the well you have pictured above?  If no water tight seal, water will be sloshing around and out of the well as you're underway...including your live bait.


Notice the black tube exiting the livewell horizontally, out and over transom

[Capt. Bob]

1. I'd like to have my pump mounted to the bottom of the livewell, a couple feet up from the strainer/seacock.  Any issue with this and the pumping power to bring water up?

That will depend on the model pump you use. I believe my Shurflo is stated to pull a 6' head. It acts as both a washdown and a live well pump. It's located about 3' from the thru hull.

That stated, drawing #1 will work with a proper pump.

2. I understand the pump is not bidirectional.  Water can't go back in the pump and out my thru-hull.  Correct?  In diagram #2 I'm thinking I could use a T fitting to send overflow water back out the thru hull.  Instead of over the back of the transom.  Would this work?  Assuming that if the pump was on in this scenario, it would bring in water from overflow and new water from thru hull which could be an issue...

Drawing #2 is hydraulically unsound. Even if the pump overcomes both the air in the pickup from the thru hull and your overflow line, it would eventually become a closed circuit and overflow out the top as Jason stated above. Deep six that design.

 First, depending on the pump type, water can indeed drain back through it. Rule (and probably other manufacturers) make a pump that is designed to be placed outside the hull (in lieu of a thru hull). It is mounted to the transom and has a pipe that extends out the bottom for water pickup. These are displacement type pumps (as bilge pumps are) so yes water can "flow' in both directions but not at the same time. Pump running, it flows into the tank. Pump idle, the tank will siphon back out through the pick up and pump assuming no valve is installed to prevent the flow. I had this set up on my CCP but that's another story.

You will be best served if you use drawing #1 and again as Jason stated, plan on a top.

Good luck.

[CTsalt12]

It's a Rule Tournament Series 1100 GPH, and it does have a fitting for livewell pump and livewell like Bob's.  Interesting it allows 2 way flow.  The product specs cite 790 GPH at 3.5  feet so should be okay.  Interesting another similar tournament series model says you need to mount it below the waterline, but not this one.  Although my pump will be very close to the line. The stern hatch tops will act at the livewell top, and I've added some gaskets.  Will update with pictures so you all know what I Mean, perhaps helpful for other members with 175s, assuming this works out.

Since the pump allows a 2 way flow, do I need an overflow drain AND a drain to empty the tank?  Or will the inflow hose also act as a outflow when I need to empty it at the end o the day?

[Capt. Bob]

Is this the model?
https://www.xylem.com/en-us/brands/rule/rule-products/fc-tournament-series-removable-motor-cartridge

Please understand that the fact that this style pump will allow water to siphon back through is not a feature you would use to drain the tank. You will want a dedicated, separate drain line.

Also, this type pump will need water to be present in order to prime. That means it needs to be mounted below the waterline. The model linked above is designed to be mounted directly to the seacock. That will insure that water has flooded the impeller and will be primed. You can't have this mounted above the waterline. The rated discharge is 1100 GPH at the pump. The 790 GPH is after it has passed through 3.5' of discharge hose. It is not how far away from the water it can be in order to prime.

Good explanation of the above.   
https://www.xylem.com/en-us/support/video-library/explaining-an-airlock-in-a-bilge-hose---rule-bilge-pumps/

[CTsalt12]

Yes that is the pump I have.  I'm glad you said that.  It seems like this won't work for what I'm trying to do.  I need a self priming pump like the more expensive Shurflo type I am replacing.  Technically the pump with my design will be at or below waterline, but it will be laterally a couple feet from the strainer and prone to bends in the hose.  There's a chance the water will make its way there to prime the well.  I'll be better suited to mount it directly downstream from the strainer though.  Thanks