Condiman
05-06-2004, 09:04 PM
I found this article on some of my old disks. I thought it might have some useful information.
As hard corals grow, they secrete a calcium based skeleton, and they form this skeleton from the calcium and alkalinity they take out of the water. If you keep hard corals, you will notice both your calcium and alkalinity levels will steadily decrease as your corals consume them from the water supply. As time goes on you will find yourself adding supplements to your water to keep up with the demand of your corals. Depending on your tank load, this could be a weekly or a daily chore. The more corals you have, the more calcium and alkalinity they consume. Having a calcium reactor frees you from the hassle of adding these supplements to your tank.
A calcium reactor is a device, in this case a tube, that is filled with calcium carbonate (CaCO3) media (reactor media), aquarium water is then run through it. The saltwater from your aquarium is run through the reactor chambers where it passes over the reactor media, then from there returns to your tank as reactor effluent. Now if that's all you do, nothing happens. But, if you use CO2 and inject it into the water passing over the media, a couple of things happen. First the pH of the saltwater is lowered by the amount of CO2 injected into it. When you lower the pH of the salt water to a level between 6.5 and 6.9, a nice chemical reaction happens. The media will slowly start to dissolve, as it dissolves it releases Calcium and alkalinity into the water. Not only does it release calcium and alkalinity into the water, but they are at the exact same ratio needed to help you maintain Calcium and alkalinity levels in your tank. All you have to do is release enough reactor effluent into your system at the right pH and you can easily keep your calcium and alkalinity very steady for months at a time. Freeing you from the need of dosing daily additives to maintain your calcium levels in your tank.
Pros-cons
The pros of a calcium reactor are easy, rock steady calcium and alkalinity, no daily maintenance.
The cons are lower tank pH; most people who run ca reactors have a lower tank pH than those who do not. It's not that bad, my pH runs from a low of 7.9 to a high of 8.15. The only other con is start up cost. Ca reactors are expensive to get running, figure between $480-$550 to get started. After the setup it will run you about $12 to fill a CO2 cylinder every 6 months. Also, every 4-6 months depending on your calcium requirements, between $10 and $40 to re-fill your reactor.
At first, it might seem that the addition of calcium and alkalinity does not justify the high price of purchasing a reactor. Only you can choose, at some point it comes down to keeping up with the daily chores. It can be expensive over the year to buy additives to put in the tank. There is also your time and how much is it worth to you to be free of the daily chore of needing to dose calcium and alkalinity in your tank.
Equipment
CO2 cylinder: These come in sizes ranging from 5lb tanks to 20lb and higher. I would recommend buying a 5 or 10 lbs tank, whichever you have the room for. These can be purchased either from an aquarium supply store or a local wielding store that sells and fill tanks. When you purchase a tank, decide first to get a new tank or a used one. If you buy a new tank, you need to make sure the place that will fill your tank is going to fill your tank and not swap it out for another. If you purchase a used tank, most of the time you just bring it in and swap it for another tank, easy in easy out. Personally I have a used tank, and have not had any problems with the quality of CO2 from the tanks.
CO2 regulator: The regulator hooks into the CO2 cylinder and allows you to put the CO2 into the reactor. The regulator has two gages on it. One shows the pressure inside the CO2 tank, typically it will read around 800 psi and drop under 500 psi when it is running low on CO2. The other gage is the pressure leaving the CO2 tank. You set it to just enough pressure (measured in psi) to get the CO2 to enter into the reactor, typically between 8 and 15 psi.
Included with the regulator should be a solenoid and a needle control valve. The solenoid is used to cut off the flow of CO2 from the cylinder in case of a power failure. The needle valve is used to adjust the amount of CO2 going into the calcium reactor. In some countries the regulator is sold separately from the solenoid and needle valve, in other they can be purchased as one unit.
Reactor Media: This is the stuff you put into your reactor. There are lots of different choices for reactor media. Aragonite sand, Crushed coral, CaribSea A.R.M. and Knop KORALith. All seem to work to some level, I have used crushed coral, A.R.M. and Koralith. My preference is Koralith or A.R.M.
Tubing: you’ll need airline tubing to connect the regulator to the Ca Reactor. I’ve used normal tubing as well as those specifically designed for CO2. I’ve not noticed a difference in performance from one to the other.
pH meter/controller (optional):Reactors are run at a low pH. In order to accurately and quickly determine the pH of the reactor effluent a pH meter is generally used achieve this. You can use test kits, but in the beginning you are testing the effluent pH a lot and will quickly go through a kit. Also, having a pH meter allows you to quickly tell if your effluent pH is too low or too high.
I would also recommend your meter be a controller as well. I had not had one on my tank for over two years. After a few close disasters involving very low effluent (6.1 pH) entering the tank and dropping the tank pH down, I decided to invest in a controller. My main reason for purchasing a controller was, as the CO2 tank starts to become empty the tank pressure drops, this increases the pressure of CO2 entering the reactor, causing much more CO2 to be released into the reactor, driving the reactor pH very low. Having a controller on the reactor will always prevent too much CO2 from lowing the pH, if the pH goes too low in the reactor the controller just shuts the solenoid off, stopping the CO2 from entering the reactor until the pH has risen to a normal level.
Calcium reactor: This is the biggest piece of equipment for the whole setup. First you need to decide on a single or dual chamber design. The idea of a dual chamber is that the second chamber helps to use up some of the extra CO2 before it enters the tank. People with dual chamber reactors typically see a .2 difference in pH from the exit of the first chamber to the exit of the second. Dual chambers typically hold more media as well. Great results can be had with both designs. The choice is yours.
The reactor will also have a circulation pump, this is used to circulate the water inside the first chamber as much as possible until it exits the chamber. The more contact time with the media inside the chamber, the more calcium can be extracted from the media.
Also, the reactor will either have a bubble counter attached to the unit or you will have to buy one separately. The bubble counter is used to control the amount of CO2 entering the reactor. The bubble counter is just a tube, filled 2/3 of the way with distilled water. CO2 enters under water in one part of the counter, than leaves at the top of the counter outside the water. By having the CO2 go through the water you can see, in bubbles, the amount of CO2 that is entering the reactor. You keep track of how many bubbles per minute (bpm) enter the reactor and see how this affects your effluent. An effluent pH that is too low means you need less bubbles, too high a pH means more bubbles.
Setup
You should follow the manufacturer's directions of your calcium reactor as all reactors work a little different from one another. But here is a basic idea of how it works.
Hook up your regulator to the cylinder as stated in the regulator directions. Fill the bubble counter 1/3 with distilled water. Attach the airline tubing from the regulator to the bubble counter inlet and from the bubble counter outlet into the reactor.
Fill the chamber(s) ¾ full of rinsed media. (NOTE: rinse your gravel thoroughly to keep clouding of the tank to a minimum) and seal the reactor back up. Attach the water supply line to the recirculation pump. The supply line should go from the sump (or tank), under water, to the pump inlet on the reactor. Open the effluent valve all the way, this will allow the air to escape while filling with water from the supply line (some reactors use a pump to feed the water to the reactor, some don’t). If you are not using a feeder pump you will fill the reactor with tank water BEFORE you seal the reactor back up. If using a feeder pump, turn on the pump and wait until the chamber(s) are full of water and it is streaming out the effluent valve.
Reduce the flow from the effluent valve to the point that just drops are coming out. But do not submerge the effluent valve. Have it above the water surface dripping into the water.
Next you will plug in the recirculation pump. Open the valve on your CO2 tank, turn it until you see the pressure gage move, then give the valve another ¼ to 1/3 turn, that’s normally all you need to open the tank. Next adjust the output psi to be between 8-15 psi depending on your reactor.
Then you adjust the amount of CO2 bubbles coming out of the tank and into the bubble counter. The amount of CO2 used is dependant on the water flow through the reactor (measured from the reactor effluent). The more effluent the reactor is dispensing, the more CO2 is needed to keep the pH low. Conversely, a low effluent flow requires less CO2 to be injected. This is because the injected CO2 needs time to be mixed with all the water in the reactor chambers to lower and keep the pH at a consistently low level. A good starting point is about 20 bpm of CO2 and effluent of about 40 ml/per min.
Your reactor effluent should have a pH of between 6.6 and 6.8. Any adjustments that are made will take between 12-24 hours to be seen on your reactor, so keep this in mind when making adjustments. Tuning a reactor to can sometimes take weeks, but once the magic number for your tank is found it's pretty much set and forget.
Maintenance
Just a little maintenance is required. Once you have your calcium and alkalinity stable in your tank, you need to check the effluent every week or so to make sure the same flow is coming out as well as the effluent pH is within the acceptable range. Every 4 -6 months you need to look into changing the reactor media, if it is used up. You’ll notice the media dissolving away over time, check the reactors instructions as to how low the media can go before needing replacement. Also about every 6-8 months the CO2 tank will need to be re-filled. Look at the CO2 pressure gage on the regulator, when if falls below 500 it is time to start thinking about getting the tank refilled.
As hard corals grow, they secrete a calcium based skeleton, and they form this skeleton from the calcium and alkalinity they take out of the water. If you keep hard corals, you will notice both your calcium and alkalinity levels will steadily decrease as your corals consume them from the water supply. As time goes on you will find yourself adding supplements to your water to keep up with the demand of your corals. Depending on your tank load, this could be a weekly or a daily chore. The more corals you have, the more calcium and alkalinity they consume. Having a calcium reactor frees you from the hassle of adding these supplements to your tank.
A calcium reactor is a device, in this case a tube, that is filled with calcium carbonate (CaCO3) media (reactor media), aquarium water is then run through it. The saltwater from your aquarium is run through the reactor chambers where it passes over the reactor media, then from there returns to your tank as reactor effluent. Now if that's all you do, nothing happens. But, if you use CO2 and inject it into the water passing over the media, a couple of things happen. First the pH of the saltwater is lowered by the amount of CO2 injected into it. When you lower the pH of the salt water to a level between 6.5 and 6.9, a nice chemical reaction happens. The media will slowly start to dissolve, as it dissolves it releases Calcium and alkalinity into the water. Not only does it release calcium and alkalinity into the water, but they are at the exact same ratio needed to help you maintain Calcium and alkalinity levels in your tank. All you have to do is release enough reactor effluent into your system at the right pH and you can easily keep your calcium and alkalinity very steady for months at a time. Freeing you from the need of dosing daily additives to maintain your calcium levels in your tank.
Pros-cons
The pros of a calcium reactor are easy, rock steady calcium and alkalinity, no daily maintenance.
The cons are lower tank pH; most people who run ca reactors have a lower tank pH than those who do not. It's not that bad, my pH runs from a low of 7.9 to a high of 8.15. The only other con is start up cost. Ca reactors are expensive to get running, figure between $480-$550 to get started. After the setup it will run you about $12 to fill a CO2 cylinder every 6 months. Also, every 4-6 months depending on your calcium requirements, between $10 and $40 to re-fill your reactor.
At first, it might seem that the addition of calcium and alkalinity does not justify the high price of purchasing a reactor. Only you can choose, at some point it comes down to keeping up with the daily chores. It can be expensive over the year to buy additives to put in the tank. There is also your time and how much is it worth to you to be free of the daily chore of needing to dose calcium and alkalinity in your tank.
Equipment
CO2 cylinder: These come in sizes ranging from 5lb tanks to 20lb and higher. I would recommend buying a 5 or 10 lbs tank, whichever you have the room for. These can be purchased either from an aquarium supply store or a local wielding store that sells and fill tanks. When you purchase a tank, decide first to get a new tank or a used one. If you buy a new tank, you need to make sure the place that will fill your tank is going to fill your tank and not swap it out for another. If you purchase a used tank, most of the time you just bring it in and swap it for another tank, easy in easy out. Personally I have a used tank, and have not had any problems with the quality of CO2 from the tanks.
CO2 regulator: The regulator hooks into the CO2 cylinder and allows you to put the CO2 into the reactor. The regulator has two gages on it. One shows the pressure inside the CO2 tank, typically it will read around 800 psi and drop under 500 psi when it is running low on CO2. The other gage is the pressure leaving the CO2 tank. You set it to just enough pressure (measured in psi) to get the CO2 to enter into the reactor, typically between 8 and 15 psi.
Included with the regulator should be a solenoid and a needle control valve. The solenoid is used to cut off the flow of CO2 from the cylinder in case of a power failure. The needle valve is used to adjust the amount of CO2 going into the calcium reactor. In some countries the regulator is sold separately from the solenoid and needle valve, in other they can be purchased as one unit.
Reactor Media: This is the stuff you put into your reactor. There are lots of different choices for reactor media. Aragonite sand, Crushed coral, CaribSea A.R.M. and Knop KORALith. All seem to work to some level, I have used crushed coral, A.R.M. and Koralith. My preference is Koralith or A.R.M.
Tubing: you’ll need airline tubing to connect the regulator to the Ca Reactor. I’ve used normal tubing as well as those specifically designed for CO2. I’ve not noticed a difference in performance from one to the other.
pH meter/controller (optional):Reactors are run at a low pH. In order to accurately and quickly determine the pH of the reactor effluent a pH meter is generally used achieve this. You can use test kits, but in the beginning you are testing the effluent pH a lot and will quickly go through a kit. Also, having a pH meter allows you to quickly tell if your effluent pH is too low or too high.
I would also recommend your meter be a controller as well. I had not had one on my tank for over two years. After a few close disasters involving very low effluent (6.1 pH) entering the tank and dropping the tank pH down, I decided to invest in a controller. My main reason for purchasing a controller was, as the CO2 tank starts to become empty the tank pressure drops, this increases the pressure of CO2 entering the reactor, causing much more CO2 to be released into the reactor, driving the reactor pH very low. Having a controller on the reactor will always prevent too much CO2 from lowing the pH, if the pH goes too low in the reactor the controller just shuts the solenoid off, stopping the CO2 from entering the reactor until the pH has risen to a normal level.
Calcium reactor: This is the biggest piece of equipment for the whole setup. First you need to decide on a single or dual chamber design. The idea of a dual chamber is that the second chamber helps to use up some of the extra CO2 before it enters the tank. People with dual chamber reactors typically see a .2 difference in pH from the exit of the first chamber to the exit of the second. Dual chambers typically hold more media as well. Great results can be had with both designs. The choice is yours.
The reactor will also have a circulation pump, this is used to circulate the water inside the first chamber as much as possible until it exits the chamber. The more contact time with the media inside the chamber, the more calcium can be extracted from the media.
Also, the reactor will either have a bubble counter attached to the unit or you will have to buy one separately. The bubble counter is used to control the amount of CO2 entering the reactor. The bubble counter is just a tube, filled 2/3 of the way with distilled water. CO2 enters under water in one part of the counter, than leaves at the top of the counter outside the water. By having the CO2 go through the water you can see, in bubbles, the amount of CO2 that is entering the reactor. You keep track of how many bubbles per minute (bpm) enter the reactor and see how this affects your effluent. An effluent pH that is too low means you need less bubbles, too high a pH means more bubbles.
Setup
You should follow the manufacturer's directions of your calcium reactor as all reactors work a little different from one another. But here is a basic idea of how it works.
Hook up your regulator to the cylinder as stated in the regulator directions. Fill the bubble counter 1/3 with distilled water. Attach the airline tubing from the regulator to the bubble counter inlet and from the bubble counter outlet into the reactor.
Fill the chamber(s) ¾ full of rinsed media. (NOTE: rinse your gravel thoroughly to keep clouding of the tank to a minimum) and seal the reactor back up. Attach the water supply line to the recirculation pump. The supply line should go from the sump (or tank), under water, to the pump inlet on the reactor. Open the effluent valve all the way, this will allow the air to escape while filling with water from the supply line (some reactors use a pump to feed the water to the reactor, some don’t). If you are not using a feeder pump you will fill the reactor with tank water BEFORE you seal the reactor back up. If using a feeder pump, turn on the pump and wait until the chamber(s) are full of water and it is streaming out the effluent valve.
Reduce the flow from the effluent valve to the point that just drops are coming out. But do not submerge the effluent valve. Have it above the water surface dripping into the water.
Next you will plug in the recirculation pump. Open the valve on your CO2 tank, turn it until you see the pressure gage move, then give the valve another ¼ to 1/3 turn, that’s normally all you need to open the tank. Next adjust the output psi to be between 8-15 psi depending on your reactor.
Then you adjust the amount of CO2 bubbles coming out of the tank and into the bubble counter. The amount of CO2 used is dependant on the water flow through the reactor (measured from the reactor effluent). The more effluent the reactor is dispensing, the more CO2 is needed to keep the pH low. Conversely, a low effluent flow requires less CO2 to be injected. This is because the injected CO2 needs time to be mixed with all the water in the reactor chambers to lower and keep the pH at a consistently low level. A good starting point is about 20 bpm of CO2 and effluent of about 40 ml/per min.
Your reactor effluent should have a pH of between 6.6 and 6.8. Any adjustments that are made will take between 12-24 hours to be seen on your reactor, so keep this in mind when making adjustments. Tuning a reactor to can sometimes take weeks, but once the magic number for your tank is found it's pretty much set and forget.
Maintenance
Just a little maintenance is required. Once you have your calcium and alkalinity stable in your tank, you need to check the effluent every week or so to make sure the same flow is coming out as well as the effluent pH is within the acceptable range. Every 4 -6 months you need to look into changing the reactor media, if it is used up. You’ll notice the media dissolving away over time, check the reactors instructions as to how low the media can go before needing replacement. Also about every 6-8 months the CO2 tank will need to be re-filled. Look at the CO2 pressure gage on the regulator, when if falls below 500 it is time to start thinking about getting the tank refilled.