Help with planning drain and return sizes.

[spiritwalker]

Hey gang.. Planning to order a tank here soon.. Looking at a 48x18x21 or up to a 48x20x21 volume tank (75-90ish gallons) with a 30-40 gallon sump/refugium.

I've got a new Varios8 DC pump which has 1 1/4" fittings.. The pump is rated to 2700 gph. I expect to run it fairly low with room to increase flow as needed and expect to use it to run reactors and such.

Trying to figure out what size holes to have drilled for the drain, emergency drain and return. I'd like these all hidden in the overflow box. Herbie style drain.

As I understand it, going with bigger return line will maximize flow however it seems if you want to use a lockline you end up stepping down to 3/4" anyways.. Also I'd think you would want your drains larger than your return line.

Any insight/direction would be much appreciated. Thanks!

 

[Crystal Reef Aquatics]

If you are running a Herbie, 1" to 1 1/4" drains will work great. If you want to run a bean animal, 3-1" drains. For returns either a 3/4" or dual 1/2" drains. It all depends on your desired turnover.

 

[spiritwalker]

If you are running a Herbie, 1" to 1 1/4" drains will work great. If you want to run a bean animal, 3-1" drains. For returns either a 3/4" or dual 1/2" drains. It all depends on your desired turnover.

Thanks for the response.

 

[RobZilla04]

As mentioned above, choose your drain/return setup style. Durso is simplest but also the loudest with no fail safe. Herbie is easy, quieter, and has an emergency drain. Bean Animal is also quiet, efficient, and has an emergency drain as well.

Once you've chosen your style you can better ascertain which size drain will work best for the desired turnover with a 1 1/4" return line.

 

[spiritwalker]

As mentioned above, choose your drain/return setup style. Durso is simplest but also the loudest with no fail safe. Herbie is easy, quieter, and has an emergency drain. Bean Animal is also quiet, efficient, and has an emergency drain as well.

Once you've chosen your style you can better ascertain which size drain will work best for the desired turnover with a 1 1/4" return line.

As mentioned in my orig post I plan on going with the Herbie style drain.. I'd like it to support higher turnover rates. So, if we round water volume off at 100 gal and look to support a high turnover rate of 10x (?) I would want to be able to turnover 1000 gph. I don't think the pump will have any problem handling this once all the plumbing and head pressure is added but I figure the drain needs to support 1000 gph as well.. This is where I get confused as to what drain size to implement and it's relation to the return line.

Thanks.

 

[RobZilla04]

You'll be limited by the bulkhead diameter. Essentially you can put a 2" drain but if the bulkhead reduces the diameter to 1" that will restrict the flow.

If both bulkheads in the overflow are the same diameter, it makes no difference which is the drain and which is the emergency. Going back to the return, the pump will likely have the ability to over return water volume that the drain cannot process fast enough. Makes no diff if you use 3/4" or 1 1/4" return line. The only difference there will be the pump flow setting. Wider diameter equals higher pump setting to get the same head pressure as narrower pipe with a lower setting.

Hopefully that all makes sense & maybe someone with a little more knowledge can chime in here.

On a side note I don't believe there is any evidence that 10x turn over is any more beneficial that 5x turnover.

 

[spiritwalker]

Thanks. I ended picking up a 120 gal lee-mar used. the overflow is drilled for 1 1/4" and 3/4" bulkheads.. i guess the 1.25 will be the main drain and the 3/4" will act as the emergency overflow. really seems like they should be the same size but I guess a full blockage on the main overflow is not very likely especially if using a strainer. the return hole is drilled in the eurobrace and is sized for 3/4" bulkhead.. If I just plumb up and over without a bulkhead I could go larger.