The End of 2-Part

[CalmSeasQuest]

Over the years I've switched from a CA reactor, to dripping kalk (a few years later when I got back into the hobby), then a Kalk reactor, then 2-part on dosing pumps....got great results with all but I have to say, I got tired of all the mixing and dosing and decided to go back to a CA reactor a few years ago (Korallin 1502, milwaukee regulator).....one of the best maintenance decisions I made for my tank, took about 2 week to get it dialed in right, but other than refilling it, I haven't had to touch it since I set it up. My pH did drop a bit due to excess CO2 (from 8.1-8.3 to 7.8-8.2) but it didn't seem to have any negative effects on the tank.

I agree with the importance of Kalk. I saturate my ATO with Kalk (managed via an Osmolator.) The Kalk does a good job of countering the pH depressing effect of the CaRx - especially at night. My diurnal pH ranges from 8.0 ~ 8.2 (with reactor running at ~6.50.) Without the Kalk I beleive it would be more like 7.8 ~ 8.0.

I've been running a calc reactor on my tank for about 2 years now and haven't had any issues with alk spikes. Also, you can add magnesium flakes to your media so that you don't have to dose as much, if any, mag.
CJ

Great point CJO - I thought about adding MAG (Dolomite) to the CaRx, but decided against it. I've read that Dolomite dissolves at varying (lower) pH than Ca media and as this was my first attempt with a CaRx, I wanted to eliminate as many variables as possible to speed the learning curve. Instead, I add BRS MAG monthly.

Would this be ideal on a new tank? I'm a noob with dosing

I think it might depends on your definition of "noob". If your new to marine tanks, I think I would gain some experience before tackling a CaRx (2-part dosing is much simpler.) I'm 20 years in the hobby and still learning everyday.

 

[jaysauce]

How is the setup going so far? Just ordered my Geo 612 from premium aquatics and need to figure out how I want to feed it. I was thinking about T-ing off my return plumbing but you seem to be doing fine with the aqualifter so I might end up going that route. My tank is a 50g as well. What is the reason you use the suction filter and how often do you clean it? Do you think placing the needle valve on the inlet tubing vs the outlet tubing is better?

 

[CalmSeasQuest]

How is the setup going so far? Just ordered my Geo 612 from premium aquatics and need to figure out how I want to feed it. I was thinking about T-ing off my return plumbing but you seem to be doing fine with the aqualifter so I might end up going that route. My tank is a 50g as well. What is the reason you use the suction filter and how often do you clean it? Do you think placing the needle valve on the inlet tubing vs the outlet tubing is better?

The last 6 months has been very educational. I've encountered some problems (hopefully soon resolved) and learned that running a CaRx on a small tank requires much more precision than on a typical larger build. Here's the rundown,

My 612 suffers from a small air leak. It's drawing enough air that if I didn't bleed the reactor (slightly loosening the pH probe holder and allowing gas to exit) the circulation pump would fail after a few days. It's taken months to get it nailed down. Through the process of elimination, it appears to be somewhere in the manifold. George (GEO) has agreed to ship me a replacement manifold - I'll post the results once received and installed.

While the Aqualifter worked well, I found that I was unable to get the precision needed - even using a high quality needle valve. I run the reactor at 6.45pH @ 25mL/Min (30 bubbles/min @ 2PSI.) This maintains a steady 10.7 ALK and 440 Ca (I've tested virtually every day at 7am using a Hannah 755 for the past 4 months.) While the Carbon Doser regulator allows for the precise bubble count / reactor pH - Because my water volume is so small, even tiny changes in flow left unchecked would result in large ALK swings. I simply wasn't able to maintain an exact-enough flow rate using a needle valve.

My solution was the installation of a Cole Parmer 7553-80 Masterflex pump and variable controller fitted with a 77200-60 Easy Load II pump head. Using L/S 180 Norprene tubing, I'm able to dial in exactly 25mL / min output using about 1 RPM on the pump (dead silent.) This combination allows me to maintain the exact settings desired, with virtually no variation (+- .01 reactor pH and the ability to eliminate regulator solenoid cycling.) It also provides the flexibility to control output from 0.06 to 2300 mL/min by increasing pump RPM (turning a dial for 1 to 600 rpm) and using different diameter tubing.

Constant use peristaltic pumps are not cheap (usually available for a fraction of their retail price on eBay), but in my opinion, are the single best option for feeding a CaRx - especially when utilized on smaller systems. I'll never use anything else.

One other recommendation - For my heavily SPS stocked tank, maintaining pH with a CaRx is tough and requires the use of Kalk. I use a CO2 scrubber and Kalk saturated ATO, a reverse-lit sump/fuge and run the CaRx effluent into a turbulent area just upstream of the Skimmer to aid in degassing any remaining CO2. Even with these steps, my diurnal pH swings average 7.85~8.0 (tanks are in a living room averaging ~550ppm CO2.) While certainly not ideal, my tanks are doing very well at these lower pH levels. That said, I would not be able to maintain acceptable pH levels without the Kalk.

 

[jaysauce]

What would be your other option instead of a Cole Parmer or peristaltic pump? Maybe something budget minded =)

Thanks for the update!

 

[jaysauce]

Did you need to use some kind of bubble counter fluid with the Geo reactor? Or does the bubble counter tube just fill up with tank water and that is the media through which the bubbles flow?

 

[CalmSeasQuest]

What would be your other option instead of a Cole Parmer or peristaltic pump? Maybe something budget minded =)

Thanks for the update!

In theory, any pump that provides a consistent output will work however, I found that when dealing with very small water volumes (in my case ~50 gallons) - even small variations in flow had significant impact on alkalinity rates. A peristaltic pump provides precise control. If it were me, I'd be watching ebay for inexpensive Cole-Parmers.

When dialing in - Get used to testing alk daily around the same time of the day (diurnal swings can be ~2dKh.) It takes a while to get things stabilized. A Hanna Alk Colorimeter is a great investment. Most importantly - Resist the urge to adjust your Alk and Ca using the reactor. Set it where you want using dosing then use the CaRx to maintain those levels.

Did you need to use some kind of bubble counter fluid with the Geo reactor? Or does the bubble counter tube just fill up with tank water and that is the media through which the bubbles flow?

With the GEO, the bubble tube will fill automatically when the reactor is filled. No need to do anything special.

 

[jaysauce]

Cool. Thanks for the info.

 

[aquafrags]

You have the most stable reactor in the market, I have used three models of geo 612,618,818. The 612 is the best of the bunch for consistent numbers. My suggestions go with the maxi jet, works the best and most economical option, just soak and clean every six months. Also to make things easier ad the mag from zeo, keeps all three params dialed in!!

 

[CalmSeasQuest]

Finally...

It took months, but I finally found and resolved the air leak. Turns out it was not in the CaRx manifold, but in the Carbon Doser regulator (I think the low pressure gauge had a tiny leak.) Aquatic Plants advance shipped a replacement and voilà...no more air

This setup is now running perfectly, I couldn't be happier with it. The GEO 612 / Carbon Doser / Cole Parmer combination makes running a reactor on smaller tanks very simple.

 

[davework]

I used my return pump to feed the reactor also. A small tee into the return line and then you can set your needle valve.

 

[CalmSeasQuest]

I've been asked to provide photos of previously when the system was on 2-part for comparison to it's current SPS load now using the CaRx. First let me apologize for my lack of photo skills...

Here's the GEO 612 sitting beside the 7 gallon ATO bucket containing RO/DI super-saturated with Kalk (140mL vinegar/7 gallons.) The Cole-Parmer peristaltic pump and controller are directly above and the to the left of the 612. The 5lb CO2 tank and Aquarium Plants Carbon Doser regulator sit behind the 612. All of this is located in the cabinet under the FT.

Here is the system maintained using 2-part.. This photo was taken about a year ago.

Here it is currently with the calcium reactor. Sorry for the lack of color, it's difficult to tell much detail as the AI LEDs were still in the sunrise mode when I snapped these photos.

The DT contains 3 large Monti Caps (left rear corner) that grow so quickly as to require "pruning" every couple of months. There are also 2 clams, a large Squamosa (bottom right) and a medium Maxima (top right.) This is in addition to the ~200+ Acro and Acan Frags in the FT. FWIW, based on the growth of the SPS, I would estimate the Alk and Ca demands to be much greater than when the system was maintained using 2 part.

Wow, In comparing these photos, I just realized how much the Maxima and especially the Squamosa has grown in the last year.

 

[CalmSeasQuest]

It appears the addition of 10% Dolomite (ZeoMag) to the GEO 612 is helping support Mg levels at ~1350. Prior to adding the ZeoMAg, with ~30% monthly water changes (RC), I was dosing 200~300mL BRS Mg solution monthly. No additional MG was required this month.

I'm glad to see signs that the ZeoMAg is dissolving - I was concerned that the 6.68pH that I run the reactor at might not be low enough for the ZeoMAg. I'll wait and see what happens next month before drawing any conclusions.

 

[CalmSeasQuest]

It looks like the ZeoMAg is working. This morning's Mag test showed 1650, with only normal water changes. I'm especially impressed as I've added quite a few new Frags in the past month and the 612 is keeping up just fine @ 6.68 pH.