Mixing station questions

[Kongar]

Hello all,

A couple of mixing station questions - probably noob-ish, but I haven't run across these answers in the many threads I've read (didn't read them all, but ya).

1) I have these tanks:

How do you all deal with vacuums and over pressurization? The cap has a little spring loaded ball in it. It pushes into the cap towards the bottom of the tank. I'm assuming this prevents a vacuum from forming. But what about overpressure? When I transfer from the RODI tank to the salt water tank - won't this pressurize the salt water tank? For those of you who have this style tank - do you purposely leave the cover loose? Do you intentionally make a poor seal somewhere so air can escape? Nobody talks about this and I'm curious why it's not more of a problem...

2) Does anyone know of an external pump that can prime itself? Specifically, one that can draw water UP against gravity? My space is very limited, and I'd like to mount the transfer pump above the tanks. I'm thinking like directly above the tanks, so in this case it would pull the water from the bottom of the tank up about 36 inches. I think all the external pumps I've seen can't draw water up like this?

3) Everyone cuts into the bottom of the tank close to the bottom - but it appears in everyone's pictures that you could never really drain the tank totally. Deal with it? Or are there clever ways to pump the tanks as close to empty as possible? I was wondering what would happen if instead people cut into the tanks just a little bit higher, and used an elbow on the inside of the bulkhead to turn 90 degrees down (so that it's flush against the bottom - but maybe lifted just a 1/4 inch off the bottom) Anyone done something like this with success? How much of a gap did you leave?

4) How do you balance the size of your pump if you're going to pump say 75ft to your display tank? I'm wondering if a Jabeo pump can push the water that far horizontally. But I'm also wondering if say an Iwaki pump is going to be overkill with 20 gallon mixing containers. I'm worried about too much flow for mixing purposes. The smallest Iwaki is 492 GPH, or 8 gallons a minute. So I circulate almost the entirety of one of these 20 gallon mixing tanks every two minutes? Is that excessive or just right? Seems like a lot of flow to me...

Stupid questions - but these white tanks aren't cheap and I'd rather try to avoid mistakes before cutting into them
Thanks!

 

[homer1475]

Can't answer the pressure part as I use brutes, but I did win a huge MRC external pump here on R2R. I use it on my mixing station(40g Brutes), it's way overkill but I can mix my barrels in about a half hour. The size of the pump I don't think matters as long as you can reach your tank.

I'm not sure about a pump that will pull water, most are gravity fed.

 

[mcashatt01]

I'm in the middle of planning the same project so no real life experience to share.

1. I'm curious about pressure as well.

2. As for auto priming, I wouldn't think this would ever be an issue as long as you are plumbing the pump in to the bottom of the tank. RODI will fill the tank from the top.

3. I believe you just deal with it.

4. Worried about this one also.

 

[KStatefan]

I installed some vents on the top pf the tank.

You would have to switch to a different type of pump that was self priming. Centrifugal pumps are not.

I just deal with it. This summer I am going to take it apart and pressure wash the inside.

I use a Sicce ADV 5.5(1450 GPH @ 0 head) for my mixing station 55 gallon tanks.

 

[dwest]

Hello all,

A couple of mixing station questions - probably noob-ish, but I haven't run across these answers in the many threads I've read (didn't read them all, but ya).

1) I have these tanks:

How do you all deal with vacuums and over pressurization? The cap has a little spring loaded ball in it. It pushes into the cap towards the bottom of the tank. I'm assuming this prevents a vacuum from forming. But what about overpressure? When I transfer from the RODI tank to the salt water tank - won't this pressurize the salt water tank? For those of you who have this style tank - do you purposely leave the cover loose? Do you intentionally make a poor seal somewhere so air can escape? Nobody talks about this and I'm curious why it's not more of a problem...

2) Does anyone know of an external pump that can prime itself? Specifically, one that can draw water UP against gravity? My space is very limited, and I'd like to mount the transfer pump above the tanks. I'm thinking like directly above the tanks, so in this case it would pull the water from the bottom of the tank up about 36 inches. I think all the external pumps I've seen can't draw water up like this?

3) Everyone cuts into the bottom of the tank close to the bottom - but it appears in everyone's pictures that you could never really drain the tank totally. Deal with it? Or are there clever ways to pump the tanks as close to empty as possible? I was wondering what would happen if instead people cut into the tanks just a little bit higher, and used an elbow on the inside of the bulkhead to turn 90 degrees down (so that it's flush against the bottom - but maybe lifted just a 1/4 inch off the bottom) Anyone done something like this with success? How much of a gap did you leave?

4) How do you balance the size of your pump if you're going to pump say 75ft to your display tank? I'm wondering if a Jabeo pump can push the water that far horizontally. But I'm also wondering if say an Iwaki pump is going to be overkill with 20 gallon mixing containers. I'm worried about too much flow for mixing purposes. The smallest Iwaki is 492 GPH, or 8 gallons a minute. So I circulate almost the entirety of one of these 20 gallon mixing tanks every two minutes? Is that excessive or just right? Seems like a lot of flow to me...

Stupid questions - but these white tanks aren't cheap and I'd rather try to avoid mistakes before cutting into them
Thanks!

1. My tanks have vented lids.

2. I don’t know of a pump like that. Maybe you can use a strong powerhead inside the container?

3. My drain has the 90 degree elbow you describe. I can get all but a gallon or so out. My storage tanks are 105 gallons.

4. I wouldn’t worry too much about horizontal runs, but definitely size for the amount of water height above the tank. My system uses a mag dive 9.5 for mixing. Then my Spectrapure liter meter 3 is used for my ATO/ AWC from the water storage to the sump.

 

[Gp!]

2) Does anyone know of an external pump that can prime itself? Specifically, one that can draw water UP against gravity? My space is very limited, and I'd like to mount the transfer pump above the tanks. I'm thinking like directly above the tanks, so in this case it would pull the water from the bottom of the tank up about 36 inches. I think all the external pumps I've seen can't draw water up like this?

I use a diaphragm transfer pump for this.

The model is SHURflo Industrial Pump - 198 GPH, 115 Volt, 1/2in, Model# 2088-594-154

They don't come wired and they aren't continuous duty so you need to limit the run time with your controller but they do what you've asked.

It sounds like my mixing setup is different than yours though. I only use this pump for transfer, not to mix

 

[rsumner]

1. I use Norwesco tanks and they have a vented lid to prevent over pressurizing the tank. Honestly, you could drill a very small hole in the top of lid to solve the same problem here.

2. The only pump that I know of that is self-priming and can pull water up vertically is a transfer pump. http://www.aquatec.com/pumps/transferpumps.html. I don't know of these are salt-water safe though.

3. If you are mounting your pump at the top of the tank, I'm not sure why this matters. If you're thinking of using a diaphragm pump mounted above the tanks, then why not run a tube or pipe from the top of the tank all the way to the bottom to pull water from the bottom of the tank and then dump it back on top. My next mixing tanks will be dome or cone bottom to overcome this problem.

4. The transfer pump can handle significant head pressure but you sacrifice GPM transfer rate.