Calcium Reactor tuning - Need help!

[amps]

Hey guys,

I've got a 180 gallon tank that stocked literally a handful of SPS frags. None are larger than a couple inches. There is a ton of coraline growth however.

The issue is my Avast Calcium Reactor. Despite the fairly low load, I've had a near impossible time using the reactor to maintain my Alk levels. Alk is constantly dropping by 0.1-0.2DKH a day and despite tweaking the settings on my reactor, nothing seems to change. Before I go and add a large batch of corals, I want to make sure I have the reactor working properly.

My reactor setup is as follows:

-Avast Marine Calcium Reactor with secondary chamber
-Seachem 'Large' media
-PH Probe monitored by my Apex
-Kamoer FX-STP 2 feed pump
-Quality dual-stage CO2 regulator with a Swagelok needle valve.

My current settings are 35ml/min and 6.77 PH (measured between the main chamber and the secondary). I finally got around to measuring the effluent and it came out as a measly 12.8 DKH! No wonder my tank keeps dropping. Where should I be making changes? Raising the flow rate seems to drop the effluent DKH and I worry about melting the media if I start going lower with the PH. I just don't know where to start...

 

[KStatefan]

@jda has a nice write up on calcium reactors. I do not think he uses PH at all in the tuning.

Calcium Reactor Thoughts and Tuning

Some copied and pasted stuff from over the years. I will try and keep this document green and updated from time to time. If anybody has any suggestions, send me a PM on RC or r2r - jda on both. Feel free to send this link to anybody who might need it. Preface: This is for people who want to l...

docs.google.com

 

[PeterC99]

I have a high Alk demand tank. Here’s where my solenoid comes on/off based on pH

 

[Water Dog]

What is your bubble count? I would suggest slowly increasing it incrementally and testing after each bump. Keep doing this until you raise your effluent dKH to a point where your desired tank dKH is maintained.

 

[amps]

What is your bubble count? I would suggest slowly increasing it incrementally and testing after each bump. Keep doing this until you raise your effluent dKH to a point where your desired tank dKH is maintained.

I don't have a bubble counter on this regulator setup but judging by the PH readings, the flow seems to be really consistant. I'll start increasing it a bit by bit. Thanks!

 

[Water Dog]

Do you have a bubble counter on your calcium reactor? If not, grab yourself one of these…


I always keep one on hand for testing when I build a new dual stage regulator.

 

[jda]

Using pH is perhaps the hardest way to run a reactor. The probe is the cheapest and weakest link in the deal and turn the regulator on/off to dump and then go dry with co2 is wasteful and can yield inconsistent results.

If you are open to just hand tuning the thing, it is very reliable and easy, once you get the hang of it. There is a paper in my signature that you can browse through where you basically only test effluent dKh, figure out a magic number of bubbles and output (drips or MLs) and then you raise/lower in that ratio until you meet your tanks needs. It seems hard at first, but then you just get it.

If you still want to go with the pH probe, then I will bow out and wish you good luck.

 

[outhouse]

After a decade on my 210, I just set a bubble a second, and a fast drip into my skimmer return. ph probe never used. You can see if your melting your media to fast. to slow a drip and you clog your valve to often