How does a calcium reactor work?

[auto_loader]

Ive read that using a CA reactor makes it easy to control CA and Alk. I still dont understand the mechanics of a CA reactor or how it works. Can someone explain or direct me to some good info?

 

[Ben1]

Ill try to make this simple. A CA reactor is a tube filled with argonite media. Water is pumped through at a slow rate and dripped back into the tank. A second pump recirculates the water in the reactor and mixs C02 within the reactor. A Co2 bottle leads to the reactor bubble counter, with the correct amount of bubbles per minute in line with the amount of water exiting the reactor lowers the PH of the reactor water to 6.5-7 range. In this range the PH in the reactor is low enough to dissolve to argonite media, thus adding CA/ALK and trace elements to your tank on a constant basis.

HTH, P.s Check the library.

 

[Iron]

yup the low ph melts the cc= adding calcium and everything corals are made of or most

 

[John G]

Auto-loader, Ben explained the reactor nicely. I have mixed feelings on how well they work. I bought one in hopes to minimize the need to add calcium and buffer. Mine does a good job of maintaining my calcium levels at 450 +/- and in a way maintains my alkalinity, but only at 8 - 8.5 dkh. I like having my alk. at approx. 10, so I still have to buffer.

 

[randy holmes-farley]

John:

It's odd that the tank would be OK long term with a calcium reactor and substantial alkalinity additions.

Unless you are doing something unusual in the way of acid additions, I can't see why that works. Calcium reactors necessarily are exactly balanced with the needs of calcifying organisms. If you add alkalinity some other way, the tank would logically trend to low calcium and high alkalinity.

How large are these alkalinity additions? Maybe they are small enough to not be problematic (i.e., not be noticeable), or maybe they are even small enough to just balance the acid produced in the nitrogen cycle.

 

[John G]

Randy - You have piqued my interest. Although I've read and researched alot, I must admit the calcium/alkalinity issue still confuses me somewhat. First, I think my reactor does balance the cal/alk based on the tank requirements as you mentioned. It is just at a level of alk (8-8.5 dkh) that I consider a bit low. I want to ensure I have a high enough level of carbonates for proper calcification. So I add 1.5 teaspoons of Seachem Reef Builder twice a day (with evap water) to maintain at 10-10.5.

One thing that does confuse me is my tanks seems to "use up" alkalinity much faster than it does calcium. I can overdose buffer to get my alk up to 14-15 dkh and within 1-2 days it is right back at 8-8.5. Whereas the calcium levels will change very little.

Any input you have on this issue is greatly appreciated. (anyone else too!!)

 

[Gatortailale1]

John,

2 Q's: What type of ALK test/brand name are you using? I know fastest and Salifert's results measure differnet/ show different results. One is dkh and can't remember scale of other one. on fastest, I'm at around 8-9 and Salifert i'm like 13.
and What brand of media are you using?


Randy: What brand of media are you using. Also, do you think it makes a difference in brand of media used?

I hope to bring my new coralhound reactor on line this weekend. I purchased the Knop Koralith Media.

[ December 20, 2001: Message edited by: Gatortailale ]</p>

 

[randy holmes-farley]

John:

In general, alkalinity will be used up faster than calcium when making calcium carbonate.

If all of the (400 ppm) calcium in a tank were used up to form calcium carbonate, it would use up 20 meq/L of alkalinity. No tank has anything close to that. Using only 40 ppm of calcium will use up 2 meq/L of alkalinity. That may be the effect that you are observing about dropping rates.

Gator:

I use limewater, not a reactor, so I don't use any "media" at all.

 

[ReefStar]

I have a few helpful comments. I recently switched the media in my reactor to Caribsea. It has now been threee weeks. I could never get my alk higher than 3.8meq/l or so. After I switched to Caribsea media, my alk has climbed to 4.5meq/l, which is even a little higher than I want. I also run the PH in the reactor at 7.0 - 7.1. So the media absolutely makes a difference. I also use Salifert test kits. I have tried quite a few and they seem the most accurate and consistent. So if you cannot get your alk higher, maybe you might want to consider replacing your media. It is not too expensive (<$20). Hope this helps!

 

[John G]

Gator - I use the SeaChem Reef Status test kit for both alk and calc. I also use a Tropic Marin calcium test kit onci in a while. The two calc. kits give results within 20-25 ppm. As for media, I am using the Carib Sea ARM. Even though Joe S. has had good results with this media, and mine aren't too bad, the one thing that sort of bothers me is that after 3+ months of operation I have not seen much, if any disolving of the media. i.e., the level of media has not changed.

Randy - thanks for the explanation of alk usage!!