External pump recommendations for mixing station

[HarlequinTusk]

I'm building a saltwater mixing station. The tank is on the same floor so head pressure is only a few feet. I have already purchased two 65gal upright tanks to act as the RO/DI and SW Mixing tanks. Like all SW mixing tanks, the pump is dual purpose; (1) pump the SW mix to the display tank (or sump), and (2) circulate the SW mix. What size external pump should I consider?

And a followup question. Does anyone have any recommendations for the SW mix tank "return" pipe? In other words, should I just pump it back to the top of the tank, or should I have a pipe inside the tank that distributes the water to different locations inside the tank? Thx

 

[mcgyvr]

Hard to go wrong with this type of setup with pump in the middle an tee'd out to each/valved.. (first image I found)
https://c1.staticflickr.com/7/6011/5948245488_e3ce712bd2_b.jpg
and a pan world/blueline/iwaki pump..

I personally use a nice Eheim 1250 on mine but I'm only dual 20g tanks as my system isn't as large..

 

[Salty Waffles]

If you don't mind the noise Mag pumps are an affordable option.

And a followup question. Does anyone have any recommendations for the SW mix tank "return" pipe? In other words, should I just pump it back to the top of the tank, or should I have a pipe inside the tank that distributes the water to different locations inside the tank? Thx

When I plumbed my tank and mixing station, I plumbed my salt water mix tank to the manifold I built above my main return pump. Turn a couple valves and the fresh salt water is pumped through the return piping on up to the display.

 

[outy]

Find yourself a used Iwaki md55 it will do the job quickly, and as a mixing pump will likely never wear out.

I use a 15 year old one I bought used and had as a return pump for a decade. Does a 100G a few feet high under 5 minutes.

My 100G water changes are 10 minutes start to finish. [less mixing salt in a 100 G Rubbermaid stock tank]

 

[muttley000]

I used an iwaki 55 also, but only because it is the same as my skimmer pump. I suggest using the same pump you have elsewhere as it is a way to get an often expensive spare part doing work in a non critical spot.

 

[slief]

+ 1 for Iwaki or similar. I am using a Little Giant 4MD on my mixing station. I've had that pump for nearly 25 years now. It ran full time on my system for around 17 years before being shelved in favor of more efficient pumps and then put onto my mixing station several years ago.

 

[HarlequinTusk]

If you don't mind the noise Mag pumps are an affordable option.

I have a few MagDrive pumps, but I thought they were "submersible only".

When I plumbed my tank and mixing station, I plumbed my salt water mix tank to the manifold I built above my main return pump. Turn a couple valves and the fresh salt water is pumped through the return piping on up to the display.

I'm actually asking about the plumbing inside the SW tank. When I circulate the water back into the tank, I want to mix it up well as opposed to just dropping it back to the top of the tank.

 

[Salty Waffles]

I have a few MagDrive pumps, but I thought they were "submersible only".

Both Mag pumps I have say inline or submersible on the boxes. One is a 10 yr. old Mag12, the other is a 1 yr. old Mag3. I'm using the Mag12 on my mixing station now after starting with the Mag3 which was totally underpowered.

I'm actually asking about the plumbing inside the SW tank. When I circulate the water back into the tank, I want to mix it up well as opposed to just dropping it back to the top of the tank.

I hear ya. Good call.
What I did was go through the top edge of my 25g salt mixing tank with PVC and sealed with a uniseal. Inside the tank I made a tree with PVC. Four "arms" of the tree have 90* fittings with caps on them with holes drilled to jet water at the bottom. When I did mine, I initially had two other legs with pvc spray bars towards the top that I made to keep water moving top to bottom. I took them off when the Mag3 was in, but plan on reinstalling them eventually.

Overall, it works quite well. And my Mag12 is actually rather quiet compared to the Mag3. In fact, I left the salt tank mixing for 2 days before I realized I had left the pump on.