calcium reactor media maintenance

[Rick O]

For those of you that have been running a ca reactor for over a year what kind of maintenance are you performing on your media? I've been having some low ca/alk issues lately and tweaking my flow/bubble rates hasn't helped much. I thought I might have compacted or stopped up media so I just took it out and replaced it. What are the rest of you doing and how often?

TIA

[tdwyatt]

Originally Posted by Rick O

I thought I might have compacted or stopped up media so I just took it out and replaced it. What are the rest of you doing and how often?

TIA

Once a year, back flush the media and replace up to about 3/4 of the column height. Clean the pump out and test it for flow rate about once every 3 to 4 months. If you have a fine adjustment valve for the effluent, make sure to pull it apart once every 3 or 4 months and soak it in vinegar. The amount of Ca and alk from a CO2-driven Ca reactor will be a function of the length and diameter of the calcium column, the size of the media, the actual pH of the effluent from the primary column, and the particle size of the reactor medium. Smaller size allows for larger surface area to react with the acidic seawater, but this is only a positive characteristic of the reactor media so long as the number of fines does not increase to the level where it impedes flow. Recirculation rates will definitely have an affect on the final concentrtion of Ca and alk in the effluent, so it is important to measure the actual recirculation rate of the assembled reactor as well as the actual flow rate of the recirculation pump when not attached to the reactor. As the reactor media ages, it gets smaller and smaller, such that it may get to a size that all the spaces between the larger granules slowly fills with fines, slowing or stopping adequate interstital flow. Back flushing the media will help remove any fines that are impeding the free flow of seawater through the reactor.

This has always worked for me, I hope the fines are not filling your sponge at the bottom, as this will require a complete removal of the media and a cleaning and repacking (which I do about every 3rd addition of media anyway)...

...but then again, you have so many hermatypic corals in your tank with such good growth rates, the reactor may be fine...

...and you need to consider using a kalk reactor in addition to the CO2 based Ca reactor...

[Rick O]

Thanks Tom. I did replace about half of the media with new and rinsed and strained the rest of the media. Judging from what the runoff water looked like I would say that the empty spaces between the particles of media were probably stopped up with silt. I didn't measure my pump flow rate but judging from the sandstorm at the top of the reactor before and after the service I would say there definately is a difference now. I didn't think about cleaning the effluent needle valve. I'll do that one night this week. I'll give this a couple days and see how the alk/ca looks then.

[RWD]

Rick,
I do pretty much what you do. When the reactor gets to only 1/3 full I take it apart and rinse the old media then top it off with new stuff. In the past I didn't rinse, just topped off. This caused the reactor to plug up and stop working.

BTW what type of media are you all using? I normaly use that stuff in a plastic jar sold for reactors (can't think of the name right now). But the LFS was out of it so I used plain old crushed aragonite.

[Mafiaman]

Originally Posted by RWD

.

BTW what type of media are you all using? I normaly use that stuff in a plastic jar sold for reactors (can't think of the name right now). But the LFS was out of it so I used plain old crushed aragonite.

A.R.M.

[Rick O]

I'm using ARM. I run an effluent ph of 6.7. Bob do you notice any drop off in performance before you service it? It appeared that lately I wasn't using up hardly any media.

[Mafiaman]

Rick, I would say when you first fill the chamber it looks as if it is being used up fast because of setteling kind of like a box of cereal.

[RWD]

ARM Yes, that's it
Rick, When I didn't rinse between top offs and it would get plugged up, yes there would be a drop off in performance. The co2 seemed to form large bubbles in the media column, like it couldn't circulate properly. What I think is happening is that instead of the co2 flowing through the media evenly, it sort of gets channeled throught the path of least resistance when the media gets plugged with silt. Instead of disolving a little bit of ALL the media it passes through only a small part. Just a guess. I noticed that ARM clogs up a lot faster then regular aragonite.

[Rick O]

Hmmm. I didn't think about channeling. MyReef offers a spraybar upgrade so I may need to get that.

I used Korralith in my first reactor and had a meltdown. I had been warned that it was prone to that but at the time it was the only media I could pick up locally. What a mess that was. The meltdown also ruined the circulation pump.