Help Dialing in MRC Calcium Reactor

rwessels · 12/30/2006, 11:30 PM

I have owned this CR-2 for almost 6 months now and I am having a tough time getting it right. I am sure someone here can tell me where I am going wrong.

Tank and Sump make up 360-380 gallons of water. Water changes are 10% done every 2 weeks with Oceanic Salt. Tank is 10â€™ x 2â€™ x 2â€™ with 6 250 watt HQI Phoenix 14.5K bulbs on HQI ballasts. Tank PH is 7.9 at night and 8.1 in the day. Most of my corals are SPS, but fairly small so I can't see my Ca demand being too high.

I am shooting for 3.5 meg/l Alk and 430 Ca. The reactor is 2 chambers and is being fed by a Maxijet 600 pump. Recently I bought a special connection so I can monitor the PH coming out of the first chamber. Both chambers are filled about 80% with ARM media. I have a pinpoint controller (brand new and calibrated) set at a min PH of 6.50 and a max of 6.71 that controls the Co2. Currently I have the water leaving the reactor at about 100 ml/minute. The Alk of the water leaving the reactor is only 5.0 meg/l, but I can't seem to get it any higher. It was the same at 50 ml/minute. Any more seemed to start depressing the PH of the tank and caused the Alk leaving the reactor to drop even further.

Every 3-4 days I have to bring the Alk back from about 2.8-3.0 to my target levels with baking soda and the Ca back up with Pool Hardener (Calcium Chloride).

Any suggestions would be appreciated.

KH971 · 12/30/2006, 11:45 PM

I have the same problem myself, you need to keep the output 55-60 ml a min. A bubble every sec, on the CO2 this should allow an output of 7-6.8 Ph reading out of the second chamber. My system is 300 gallons and i have the same reactor. I do get alot of O2 into my sytem so this helps my PH.

chinaman4u · 12/30/2006, 11:48 PM

Tuning your reactor
http://www.reefkeeping.com/issues/20...ture/index.php

A online reactor calculator
http://jdieck1.home.comcast.net/reactor.html

random link
http://www.reefcentral.com/forums/sh...um+and+reactor

rwessels · 12/30/2006, 11:51 PM

I will turn down the flow of the water, but I really thing the problem is that the Alk in the water leaving the reactor is too low. I worry about lowering the PH past 6.5 because I don't want to turn the media into mush (again).

jmaneyapanda · 12/31/2006, 07:32 AM

decreasing the effluent rate should increase alkalinity. Mke sure you wait a good 24 to 48 hours before rechecking your level. changes go slow with calcium reactors.

12/30/2006, 11:30 PM	#1
rwessels Registered Member Join Date: May 2005 Location: Phoenix, AZ Posts: 779	Help Dialing in MRC Calcium Reactor I have owned this CR-2 for almost 6 months now and I am having a tough time getting it right. I am sure someone here can tell me where I am going wrong. Tank and Sump make up 360-380 gallons of water. Water changes are 10% done every 2 weeks with Oceanic Salt. Tank is 10â€™ x 2â€™ x 2â€™ with 6 250 watt HQI Phoenix 14.5K bulbs on HQI ballasts. Tank PH is 7.9 at night and 8.1 in the day. Most of my corals are SPS, but fairly small so I can't see my Ca demand being too high. I am shooting for 3.5 meg/l Alk and 430 Ca. The reactor is 2 chambers and is being fed by a Maxijet 600 pump. Recently I bought a special connection so I can monitor the PH coming out of the first chamber. Both chambers are filled about 80% with ARM media. I have a pinpoint controller (brand new and calibrated) set at a min PH of 6.50 and a max of 6.71 that controls the Co2. Currently I have the water leaving the reactor at about 100 ml/minute. The Alk of the water leaving the reactor is only 5.0 meg/l, but I can't seem to get it any higher. It was the same at 50 ml/minute. Any more seemed to start depressing the PH of the tank and caused the Alk leaving the reactor to drop even further. Every 3-4 days I have to bring the Alk back from about 2.8-3.0 to my target levels with baking soda and the Ca back up with Pool Hardener (Calcium Chloride). Any suggestions would be appreciated.

12/30/2006, 11:45 PM	#2
KH971 Registered Member Join Date: Jan 2004 Location: Eatonton,GA. Posts: 824	I have the same problem myself, you need to keep the output 55-60 ml a min. A bubble every sec, on the CO2 this should allow an output of 7-6.8 Ph reading out of the second chamber. My system is 300 gallons and i have the same reactor. I do get alot of O2 into my sytem so this helps my PH.

12/30/2006, 11:48 PM	#3
chinaman4u Premium Member Join Date: Jun 2004 Location: PennStatePA Posts: 600	Tuning your reactor http://www.reefkeeping.com/issues/20...ture/index.php A online reactor calculator http://jdieck1.home.comcast.net/reactor.html random link http://www.reefcentral.com/forums/sh...um+and+reactor

12/30/2006, 11:51 PM	#4
rwessels Registered Member Join Date: May 2005 Location: Phoenix, AZ Posts: 779	I will turn down the flow of the water, but I really thing the problem is that the Alk in the water leaving the reactor is too low. I worry about lowering the PH past 6.5 because I don't want to turn the media into mush (again).

12/31/2006, 07:32 AM	#5
jmaneyapanda Commencing hatred Join Date: Apr 2006 Posts: 3,784	decreasing the effluent rate should increase alkalinity. Mke sure you wait a good 24 to 48 hours before rechecking your level. changes go slow with calcium reactors.