Measuring Growth with a Calcium Reactor

[SPSReeferMI]

I'm considering switching from 2 part dosing to a calcium reactor. However, I really like the ability to watch my Trident measure alkalinity and automatically adjust the dosing. Also, having this information handy while away from home is reassuring to say the least. I cannot seem to find this answer on the internet, so I'd like to get your take:

I'm presently dosing 200-230ML of Alk and Calcium / day. This tells me how steady changes are working or not. Is there an equivalent measure with Calcium Reactors? Examining media burn or CO2 usage is something that I'm exploring. I assume one could measure bubble count and/or ML / min pushed through reactor. I have my reservations on how accurate this would be.

Background: It took me 2 years to reach this point. It was harder than I thought to dial in all of the parameters. At the 1 year mark, I was only at 30ML / day. Little did I know that what I thought was stable was not nearly stable enough. A few minor corrections and my tank shot up to 90ML per day (I was so happy at that point). I feel that this is one of the better ways to be in touch with the overall health of my reef tank. I presently have a 150 gallon system and plan to expand to ~450 in the near future. I'm considering a switch to a calcium reactor for two reasons: Lower maintenance (a lot less mixing) and potentially less risk for failure (some suggest that 2 part is a bit more likely to result in a failure). One concern I do not have is the cost, BRS 2 part is fairly inexpensive.

 

[jda]

You could do effluent dKh and then mls of effluent per minute and multiply them for a number. These stay pretty consistent after a new tune as long as the media is not getting used up.

In the end, I am not sure that it really matters, at least for me. If was using 2345 or 2952, that means nothing to me. If corals is growing, then who cares, right? I keep the alk stable and then check calcium every few months. How much does not concern me as long as my carbonate stays about 6.8 to 7.0, or so.

 

[SPSReeferMI]

You could do effluent dKh and then mls of effluent per minute and multiply them for a number. These stay pretty consistent after a new tune as long as the media is not getting used up.

In the end, I am not sure that it really matters, at least for me. If was using 2345 or 2952, that means nothing to me. If corals is growing, then who cares, right? I keep the alk stable and then check calcium every few months. How much does not concern me as long as my carbonate stays about 6.8 to 7.0, or so.

Thanks for the reply. When your media gets partially used up, does the dKh reduce? Perhaps you’re right and it may not matter. However, I do think it’s nice to have the extra data.

 

[jda]

Output is usually very consistent until the media gets down to where there is very little left.

 

[SPSReeferMI]

Output is usually very consistent until the media gets down to where there is very little left.

Good to know. Thanks.

 

[outhouse]

I get down to a 1/3 and then rep[lace media, never measure anything, coral grows like weeds. YOU are doing the right thing for a nice SPS tank, use a ca reactor and keep measuring. your bubble count and effluent can be adjusted to match a tanks needs

 

[jda]

I got to thinking that if you use ml of effluent times dKh for a number, then you would need to monitor tank dKh too. The same tune will usually cause the tank dKh to slowly drop over a few months as stuff grows and demand increases... then you up the output from the CaRx. In any case, it is doable if you want to, but you might need to mess around with the numbers until you find something that works.

 

[SPSReeferMI]

I got to thinking that if you use ml of effluent times dKh for a number, then you would need to monitor tank dKh too. The same tune will usually cause the tank dKh to slowly drop over a few months as stuff grows and demand increases... then you up the output from the CaRx. In any case, it is doable if you want to, but you might need to mess around with the numbers until you find something that works.

Thanks for that info. I’d be reallly happy if I could go months without having to make changes

I read this thread and I am considering it as an option. It’s similar to what you are suggesting above, but giving the Apex a little bit of freedom to adjust based upon Trident test results.

 

[jda]

I don't recommend nor know how to help when using a pH probe and controller with a CaRx. I tried this and it is not reliable long term, IMO. The probe is the weakest link in this setup and it does not allow the CaRx to run efficiently with the on/off nature of the solenoid opening and closing al of the time. I recommend just leaning how to tune it and then letting it run 24/7. There is a paper attached to my signature that has a bunch of mostly ramblings about how to do this. Even if you want to use a pH probe, I strongly suggest that you learn how to tune the thing by hand first and you can use the pH probe to monitor... then after you are 100% good with using it, then you can switch it if you want.

You have to turn up calcium reactors from time to time, but they can go a long time without needing anything. I posted this on another tread today about how mine works:
People who think that a CaRx is just linear have no experienced it yet, but will. They do need to be turned up from time to time, but how often depends on your tank. Let's say that my current tank dKh is about 6.2... this means that I need to turn up by CaRx. I will turn it up a tiny bit and over the next two weeks, the tank dKh might go up to 7.4-7.8 (whatever) where is stops eventually. It will then slowly start going down over the next few months based on a variety of factors - mostly what is growing. Once the tank dKh hits the mid 6's again, it is time to turn it up again. It takes weeks sometimes to see things settle, which is why it is so hard to crash a tank with a CaRx without huge human error.

My tank dKh might move from low 6s to high 7s over several months. This is fine with me and anybody who says that you have to stay at 7.2 (or whatever) all of the time probably does not know what they are talking about. I have had tank dKh into the 5s with no real issues, but I don't like to go much over 8.

As long as stuff is growing, you always have to increase whatever you are using. I just test tank dKh about once a week and then I know when I have to turn my CaRx up. When the media hits 25/33%, it is time to change it. When the co2 bottle is really light and you can hear liquid co2 swirling around in there, then it is time for a new bottle. If you learn to tune a CaRx, then you can look at the effluent rate and bubbles and just know if it right or not - but a simple dKh test can tell you for sure.