Return pump size

[Reef Fixations]

I'm not suggesting that u go as large as a mag 18. I just wasnt sure if u thought that 600 was the absolute limit or not.

The mag 18 worked just fine for me in that specific application tho. I.also ran a 92 corner with a single HOB CPR overflow with a 1" drain powered by a blueline 55 (1100gph pressure rated pump) at about 4.5' of head.

It's definitely louder but 1" can take more than 600gph.

But if u want to maximize on dwell time then a smaller pump is fine. It all depends on the application and/or preference.

 

[Reef Fixations]

So how would a mag 18 work? Or does it operate in that range at 6 feet of head pressure?

I'm guessing it would be around 1300gph more or less at 4.5'. I had Ecosystems, ADHI and modded or DIY fuges and ran them on high and low flow and for some reason I had better results with high flow fuges (based on culerpa growth) eventho slow flow is supposed to work better because of the longer dwell times. Like everything in this hobby tho, u have to do what works.best for u and take anyone's suggestions/experiences with a grain of salt.

 

[Imbarrie]

There is a flow limitation of a 1inch bulkhead that is rated at half of what a mag 18 can supply.

 

[Reef Fixations]

There is a flow limitation of a 1inch bulkhead that is rated at half of what a mag 18 can supply.

U r right, but I don't pay that too much mind because I break that rule on almost every tank that I've ever had or have. The only time it is ever an issue is if there too many fittings or if I used a barb adapter to use vinyl tubing. Then I'm restricted to 600 gph or less. If I go straight to 1" standard spa flex then I can break that rule and run well over 1000gph without hesitation but it is louder.

 

[ming]

I don't suggest going above the 600gph on a 1" drain unless you know what you're doing. If it is getting louder, then you're likely going to ask for trouble in the future. When you go above 600gph, it starts getting the "flushing" sound because water level rises due to not draining fast enough, then it creates a siphon which can handle more then 600gph. Once that siphon breaks, you get the flushing sound. This assumes you would have enough room for water level to rise high enough to create the siphon without overflowing. The safer method, and MUCH quieter, is the herbie method which samsky has mentioned because its based off creating a siphon, and maintaining it, but this is only done with a backup drain in case anything clogs it.

 

[Reef Fixations]

I agree but I've never had an issue in the scenarios I mentioned and I dont mind a loud tank. I did say that I wasn't suggesting that anyone use a much larger pump, my point is that u aren't strictly limited to 600gph and if u do go above that it will simply become louder. In the scenarios I mentioned I never came close to overflowing one of my DT's unless there were too many fittings or barb fittings used.

I never did anything special other than making a cover for an internal or HOB overflow with a hole drilled in it to quiet it down and allow an air vent to allow water to drain and directly hooking up spa flex from.the bulkhead to the sump.

 

[Reef Fixations]

The loudest tank i had was a 75g with a 1" durso overflow and a mag 12 but overflowing wasn't an issue.

From my experience, u have an issue if water never stabilizes and never flows a a consistent rate thru the drain. In the case of a 1" bulkhead drilled thru the back of a tank with a strainer on the inside and a 90 degree barb fitting on the outside, into vinyl tubing with 600gph or less, the water in the tank would rise and every few minutes would begin to rush out and it sounded like water would surge and slow down until it rose high enough and started again. I even drilled a small air vent in the 90 fitting with about 24" of airline in it to help and it did help but it needs to be repiped for proper drainage.

 

[ming]

Thread is getting a little off
:backtotop

 

[Imbarrie]

We are dealing with acceptable constraints. And one of those is a static pressure overflow and the flow capacity of that.
This is a hobby not a physics experiment.