dosing pump for calcium reactor - where to position ?

[CTaylor]

Hi,
Do I have the pump take in water from the tank then send it to the input of the reactor? I call this push (to reactor).
Or do I have it pull from the output of the reactor and send to the tank? I call this pull (from reactor).

I've been told to use a pull method, but they may have meant pull from the tank to the reactor (which is my push).

Pushing (to reactor) makes sense to me. That's how the feed pump (power head) is set up if dosing pump is not used. If there was air / gas in the reactor for some reason then the dosing pump is sucking air if it was positioned to pull (from reactor). But it would be pushing the air and everything else out if it's set to push (to reactor). So I really want to use the push (to reactor) unless there's a real reason not to.

TY!

 

[slief]

Pull method means the pump is ahead of the reactor pulling the water through the reactor from the sump. Push means the pump is before the reactor pulling from the sump and pushing through the reactor.

Pulling generally won’t result in reactors leaking water since there is never any pressure inside the reactor. Pushing could because the reactor is slightly pressurized. I’ve run into gas or air in the reactor (possibly from vacuum leaks) when pulling and typically opt to push since I can immediately locate a leak if there ever was one. That said, I’ve never had a calcium reactor leak and I’ve set up several using peristaltic feed pumps but I always use RODI type tubing with john guest fittings for the entire feed and effluent lines. I also make sure the reactor is properly sealed.

This thread is a great resource for using a peristaltic type pump for the calcium reactor. While it does center on the Masterflex pumps, the principle is the same with any dosing pump as a feed source. You can search terms in there like pull or push and see what others are doing and why.
http://www.reefcentral.com/forums/showthread.php?t=2368618

 

[ca1ore]

Pull = after the CaRx; push = before the CaRx. I’ve done both; frankly not a great deal of difference. I do conceptually prefer pull figuring the peri tubing will be less affected by any grit or detritus coming in from the tank. I’m not always as diligent as I should be in replacing the peri tubing. I do pull on my sulphur denitrator also.

 

[CTaylor]

Very interesting. I didnt thnk of the pressure aspect on the push method. THough it seems to be less pressure than when a power head feeds the reactor like a MJ1200 and a valve is on the outflow from reactor, which is the way I've been doing it.

For about 2 months I was using my doing pump in pull method, and had a lot of air in the reactor. Then I switched back to the ph to feed the reactor. That's when I found 2 leaks. Apparently the areas where air was going in was being sucked in by maybe slightly lower pressure from the pull of the dosing pump, then water was being pushed out by the higher pressure of the ph pushing.

I'm going to do the pull method again mainly b/c the fittings allow it easiest without adapters, and it's what I used last. It's just easier to re-set that up. And I can keep the doser pump tubing cleaner.

TY!

 

[five.five-six]

I prefer return manifold tap push with needle valve method for several reasons.

Let’s be clear, masterflex pull is the Cadillac option.

That said, manifold push provides enough pressure that it tends to be consistent enough for our needs. Power heads don’t provide enough pressure and tend to be inconsistent in feed. Another advantage of manifold push is that it’s less equipment to buy, power and fail. Those masterflex pumps are the size of a halide ballast and do require occasional maintenance.


Always pull with a peristaltic pump, you may have to deal with air bubbles but many peristaltic pumps can create sufficient pressure to grenade many calcium reactors if the effluent gets clogged.

 

[CTaylor]

556
TY
I'll have to read some about manifold and masterflex...
I'm using a kamoer, pic here.
I was told to do that. There may be more $$ ones, but for the money, I was advised to get this. Is it a good one for pulling? Thats what I'm goign to re-set it up as, mainly for convenience actually on where I cna put the pump and the fittings on my reactor

TY

 

[five.five-six]

556
TY
I'll have to read some about manifold and masterflex...
I'm using a kamoer, pic here.
I was told to do that. There may be more $$ ones, but for the money, I was advised to get this. Is it a good one for pulling? Thats what I'm goign to re-set it up as, mainly for convenience actually on where I cna put the pump and the fittings on my reactor

TY

Since you already have the kamoer, run it. Most consider that the best option but you definitely want to pull.

When I say masterflex, it's like Kleenex. Includes any of the programable peristaltic pumps.

 

[CTaylor]

Since you already have the kamoer, run it. Most consider that the best option but you definitely want to pull.

When I say masterflex, it's like Kleenex. Includes any of the programable peristaltic pumps.

TY!
I tried pull, and I got air in the reactor. It might be CO2. I just re-calibrated my probe, and it may have been off 0.1-0.15. I reattached the power head to push water in, no leak out. I guess a leak in could happen with lower pressure of the doser compared to higher pressure pushing of the power head feeding it.

I'm going let the power head feed it a week and see what happens, esp now that I shouid have my pH more accurate now. If no air, I'll go back to pull of kamoer, and see what happens. I just know that whenver I had air in the reactor it has been only when I used the doser (always on pull). We'll see...

 

[CTaylor]

It's been 10-14 days I forget how long. But I did the above and am doing the pull method again. So far no air/gas/CO2 build up. Happy