# How To guide: Figure out total gal. of custom bait well



## appleguy (Jan 8, 2011)

Hey guys a friend built a custom bait tank using a 55 gallon drum and asked me how to figure out how many gallons his bait well could hold & what size pump he should use so here is how to do that if anyone else is wondering.

How to figure out how many gallons of water your Bait Well will hold. 
· Square Tank
1. ( Length x Width x Height = Total sqft (x) 7.45 = gallons
2. Example: 3ft × 2ft × 1ft = 6sqft (6 × 7.45 = 44 gallons)
3. Formula is simple (L × W × H = a (a × 7.45 = gallons)

· For a Cylinder Bait Well (A little more complex)
1. Measure the diameter of the cylinder and divide it by 2 (ex: 24in / 2 = 12in)
2. Now that number square "Multiply" that number (D) by itself (D x D) or (12 × 12) = 144)
3. Multiply the square radius by π or 3.14 ( 144 × 3.14 ) = 452.16 sq inches.
4. Multiply length inches by the square inches or 452.16 ( 24in × 452.168sqin )
5. Divide the product by 1728 (10852.032 / 1728 = 6.28 cubic feet )
6. Take the product and multiply it by 7.45 ( 6.28 × 7.45 = 47 gallons)

*NOTE: After you figure your total cubic feet you may want to take your total sqft and multiply it by 10% then subtract (-) that number from your total cubic feet to allow for empty space of water this will help when calculating which water pump to use. Example (6sqft **× 10% = .6 | 6sqft - .6 = 5.4sqft)*

When choosing a bait well pump that will pump raw fresh water from sea to tank I try to find a pump that can pump at least 33% of the total gallons of my tank within 1 minute since I use a timer switch set for 3 minutes off 1 min on. Figuring the right GPH for my needs is easy using simple math. Say I have a 26 Gallon Tank and I’m looking to pump at least 33% of fresh water into my tank in 1 minute. And if your using a timer set on 7 minutes off 3 minutes on your pumping 100% of fresh water into your tank. Here is the formula for doing this.

*26g × 33% or 26g × .33 = 8.6 GPM flow*

So I need a pump that can pump atleast 8.6 call it 9 gallons of fresh water into my tank in 1 minute. I would start with a 550GPH Pump and apply the following math to see how many GPM it can pump.

*550 / 60 = 9.1GPM*

33% or 9.1 GPM is more than enough fresh water every 3 minutes to keep your bait alive. And like I said if you’re using a timer set at 7 minutes OFF and 3 minutes ON you will be pumping 100% fresh water into your tank every cycle.


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## X-Shark (Oct 3, 2007)

Thats neat. 

Or you could just fill 5gal buckets and pour them in to see how many it would hold.  You mentioned Square [which make terrible baitwells as the bait will stack up in the corner.] Then you mentioned round. Then there are Oval which are even better. 

The recommendations on Kodiak Baitwell site is what I use.

http://www.kodiakmarine.com/products.html

360GPH for 7 to 16gal
500GPH for 17 to 30gal
1100GPH for 30 to 40gal

To much flow is as bad as not enough, as it will stress the baits also.


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## appleguy (Jan 8, 2011)

Thanks X-Shark, Just adding it because a friend asked. I have a 32 gallon built into my boat so don't really need this but if you look at Kodiak's recommendations my math is pretty much on for the pumps GPH.


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