CA, Alk, and Calcium Reactor Question

[wayne]

I've had a lifefeef calcium reactor for a few months now, and a friend just checked my CA and Alk for me. This resulted in CA of 395 and Alk of 1.94. These tests were done with a Salifert test kit. My Ph seems to be low most of the time... 7.6 in the morning and 8.1 in the evening.

I have a "burst" of bubbles in the Bubble counter about every second. I have the effluent entering the sump at a slow steady stream.

I am wondering what buffering method I need to use to increase Alk?

Also, to increase the CA, should I decrease the effluent rate (so the water circulates through the media more), raise the CO2 rate (to increase the CO2 levels in the reactor), or a combination of the two, or something else entirely.

I am not a scientist and the Calcium Reactor is new technology to me, so be gentle. The tank and most of it's inhabitants can be seen in my sig. Also, I have recently added MH lighting to the tank. They are on a total of 5 hours last week, going to 6 hours today. I have been increasing the time by 1 hour for the last 4 weeks.

Sorry for the length, but thanks for any help you can give.

[Edited by wayne on 12-30-2000 at 12:09 PM]

[MIKE]

Hi Wayne,

You don't mention the measurement standard for the alkalinity - dkh or meq/ltr? Either way, it's on the low side but not an emergency. You also don't mention how you measure ph. This is critical as ph measurements are difficult, yet important with using a reactor.

Most reactors will maintain both calcium and alkalinity. For the reactor to be performing ideally you need a few things happenin'. First, you need fresh media. I would recommend changing it every 3-5 months not matter what. The media is cheap, why not always have fresh? Second, the peak capacity of a particular reactor is dependent on two factors. First is the amount of effluent you can drip without affect tank ph. Second is the ph of the effluent, which should be around 6.5. Your ph would seem to suggest you are having co2 leakage into the tank right now.

You can increase reactor capacity by dispersing effluent co2 by dripping through aragonite, having a second non-co2 chamber, dripping in a turbulent area, and various other inventing/creative techniques.

The effluent ph is a function of the amount of co2 introduced vs. the speed of the drip. The slower you drip, the less co2 you need to attain a 6.5 ph. The opposite is true too. Also, the concentrations of dissolved carbonates will be dependent on the dwell time of the solution in the reactor. So you're always trying to strike a balance here.

What I usually recommend in running a reactor is a step by step setup:

First, using new media, start the reactor with a 1-2 ltr/hr. drip rate. Adjust the co2 to that you are getting a 6.5 ph effluent as measured by an accurate measuring device. Let it run this way a couple of weeks. This will form the baseline. Setup any effluent co2 dispersal mechanisms you plan to use and implement those.

Second, use a buffering product and a calcium additive to adjust the tank alkalinity and calcium to ideal levels.

Third, fine tune the reactor output by increasing/decreasing the effluent drip rate and co2 injection rate to maximize the reactor output (maximum flow rate without distrubing tank ph).

HTH

[wayne]

Mike,
Thanks for the response. I'll have to get Skipper to tell us whether the test is dkh or meq/ltr.

The Ph is tested with a meter and probe.

[MIKE]

Regularly calibrate properly I hope :)

[Skipper]

meq/l is the measurement.....

[MIKE]

Thanks Skipper. Kinda figured it was. Makes it even clearer that the alkalinity thing is not an emergency issue.

[Skipper]

What I can't figure is this: Wayne's tank has a tremendous coralline algae growth. I had thought that a low alkalinity would not be conducive to coralline growth.

[MIKE]

Hi Skipper,

What you are saying is true. But there's a difference between "conducive" and "none". Ideal calcification is dependent on a number of things, one of which is alkalinity. If there's enough carbonates, good ph, appropriate lighting, minimal phosphates, spores and locations, corraline will grow. With a better alkalinity, it will just grow better :) Also, I've noticed that the more common corraline species seem to do better under lower lighting levels.