So, a CaRx noob buys an A.C.R. calcium reactor...

ScottB · Apr 28, 2020

Hi Folks,

Been swearing I was gonna do it for a long time. ESV buckets are stacked to the ceiling already, but the end of that is in sight. The ACR is here, no longer leaking, and running on my 300G frag system. And Lord knows I have the time to figure it out these days.

Device: 8" stacked with about 25lbs of coral skeleton and one jug of A.R.M coarse. 3lbs of Reborn Magnesium.

The ACR setup has no reliance on bubble counting or PH probes. The only "controls" are frequency and amount of effluent dosing. Simply set how many seconds of delay, and how many seconds the valve stays open. It is "said to" run at about 6.8 ph. Pressure to the valve control module is 8 psi.

I've been trying to measure the effluent DKH. I believe it is >60dkh. I stopped at 4ml reagent on a full strength sample without color change and 2ml on a 4:1 diluted sample. Skittish about wasting more reagent as I only have one box left and I care more about system dkh anyway -- which I keep around 8.3 +-.

Question 1:
Is >60dkh effluent scary to anyone? Is it OK that I don't really know how high my effluent dkh really is? Is there a point where I risk the media turning to mush?

Question 2:
Should I use another test kit for effluent testing? Hanna goes to 20. Dilute it 1:4, test, multiply result by 4?

Question 3:
Should I shut off the APEX DOS all together tonight?
APEX doses 110ml of ALK overnight and 110 Ca during the day. Right now, the ACR is dumping ~15ml of effluent every 200 seconds. It has been running for about 4 hours. ALK has been steady at 8 over that time period (during peak photoperiod). System consumes/swings about .8 dkh each day. (Thus, a CaRx)

Question 4:
Should I test the PH of the effluent? If so, what is healthy range to expect?

Question 5:
I have a lot of named and unnamed acropora, so I will be paying attention. I will listen to suggestions of WHAT I should be paying MOST attention to.

Tagging a couple folks I've seen discussing CaRX with frequency and clarity, but feel free to tag in anyone else you think I can learn from. @jda @ca1ore

Many thanks all,
scott

jda · Apr 29, 2020

You absolutely need to learn how to measure effluent dKh. You should not be guessing. Get a Salifert Alk test kit for this - they are cheap, super reliable and easy to just keep on adding the final syringe and add the numbers together.

I have no idea how to use an "automated" CaRx and find that most them fail for most folks after a while since the pH probes are the weak link. All that I know how to do it is tune a CaRx to run on it's own with just bubbles and drops since these things can go decades without failure with just normal type maintenance.

I run 25 dKh on the effluent and I have not measured reactor pH since about the time my kids were born (they are all driving and some are in college). pH is an insignificant reading in a CaRx, IMO... effluent dKh is all that matters. At 25 dKh, there is no wasted co2 (meaning the tank pH stays high) and there is enough of an effluent rate to keep clogs and stuff way down.

jda · Apr 29, 2020

Also, you need to be waiting overnight before you retest after making a change to the setup.

X-37B · Apr 29, 2020

jda said:
You absolutely need to learn how to measure effluent dKh. You should not be guessing. Get a Salifert Alk test kit for this - they are cheap, super reliable and easy to just keep on adding the final syringe and add the numbers together.

I have no idea how to use an "automated" CaRx and find that most them fail for most folks after a while since the pH probes are the weak link. All that I know how to do it is tune a CaRx to run on it's own with just bubbles and drops since these things can go decades without failure with just normal type maintenance.

I run 25 dKh on the effluent and I have not measured reactor pH since about the time my kids were born (they are all driving and some are in college). pH is an insignificant reading in a CaRx, IMO... effluent dKh is all that matters. At 25 dKh, there is no wasted co2 (meaning the tank pH stays high) and there is enough of an effluent rate to keep clogs and stuff way down.

Follow this.
I set mine up this way 4 months ago. So simple and about as hands off and efficient as you can get.
Thanks, jda!

ScottB · Apr 29, 2020

jda said:
You absolutely need to learn how to measure effluent dKh. You should not be guessing. Get a Salifert Alk test kit for this - they are cheap, super reliable and easy to just keep on adding the final syringe and add the numbers together.

I have no idea how to use an "automated" CaRx and find that most them fail for most folks after a while since the pH probes are the weak link. All that I know how to do it is tune a CaRx to run on it's own with just bubbles and drops since these things can go decades without failure with just normal type maintenance.

I run 25 dKh on the effluent and I have not measured reactor pH since about the time my kids were born (they are all driving and some are in college). pH is an insignificant reading in a CaRx, IMO... effluent dKh is all that matters. At 25 dKh, there is no wasted co2 (meaning the tank pH stays high) and there is enough of an effluent rate to keep clogs and stuff way down.

Thank you jda. I do use salifert for testing ALK for both system water and effluent. Just down to my last box, and the LFS is out of supply as well as Amazon for the moment. (Will trade you some toilet paper for a box.

) I used 4 syringes on testing the effluent and got no color change; thus +60dkh. When I get my hands on more reagent, I will get a better effluent number.

I will say that my system ALK has stayed stable over the 18 hours of run time so far. So I got that going for me.

Agree that ph probes are PITA, and that is part of the reason I chose the aquarium engineering reactor. No probes.
The clog issue is also (hopefully) solved for in this design. It is not a continuous drip. Instead, the controller opens a solenoid and manifold pressure shoots out the effluent. I get 15ml in 2 seconds. The controller then waits 200 seconds before opening the solenoid again. These are just the default settings.

I think I will purchase a backup valve module as it strikes me as the only significant mechanical failure point. (Aside from the sicce 2.0 recirc pump which I already have a spare.)

Other than having lost about .15 in system PH, I don't have another measure of how much CO2 the reactor is wasting. It is still early, but if it settles at about .15 in PH loss, do you feel that is reasonable?

ScottB · Apr 29, 2020

jda said:
Also, you need to be waiting overnight before you retest after making a change to the setup.

Roger that. No changes made so far. On this system though, the only changes I can make are frequency of effluent release and volume of effluent release. The controller manages the CO2 injection via a float switch inside the reactor.

ScottB · Apr 29, 2020

Effluent dkh calculation -- can someone check me out on this Salifert calculation?
a) 1 part effluent to 4 parts RODI
b) Four drops of reagent #1
c) 1.3 ml of reagent #2 to get the color change
d) Therefore, 15.7 + 4.5 = 20.2 diluted
e) 20.2 X 4 = 80.8 dkh undiluted

Am I thinking about this the right way?

jda · Apr 29, 2020

This is the easiest way that I know of:

Follow the directions for the low-res mode - 2mls of tank water and 1 drop of the blue stuff, I think. If you use all 1ml of the final syringe, then get another ML and add the results together.

So if you use 1 syringe and .28 of the next one, then it is 32 for the first syring (low res) and 9.6 for the part of the second one... for a total of 31.6.

The low res mode goes to 32, so that should cover most CaRx. Also, put the remaining final solution back into the bottle - it goes further this way since I never run out of drops before the larger bottle.

ScottB · May 6, 2020

I posted this in another related thread. I am largely dialed in now; just looking to keep the system at 8 dkh and minimizing the number of cycles on the effluent valve. Anything else YOU would be keeping track of when dialing in?

	28-Apr	29-Apr	30-Apr	1-May	2-May	3-May	4-May	5-May	6-May

Avg dkh	7.7	7.6	7.4	7.3	7.3	7.3	7.7	7.7	8

Secs / day	86400	86400	86400	86400	86400	86400	86400	86400	86400
				*
Dose Seconds	2	3	4	4	6	8	10	10	12

Delay	200	300	350	350	350	400	450	450	500

Dose / day	428	285	244	244	243	212	188	188	169

Units / day	855	855	976	976	1456	1694	1878	1878	2025

APEX DOS ESV	110	10	10	40	10	10	10	10	10

Millitliters in dose					42		74
dkh of dose		82			72		70

ScottB · May 26, 2020

Just in case any of you are still watching this thread, I just heard from Julian Sprung that Reborn will ship to distributors this Friday. The problem was just supply chain, not regulatory.

Happy Reefing.

ca1ore · May 26, 2020

ScottB said:
Just in case any of you are still watching this thread, I just heard from Julian Sprung that Reborn will ship to distributors this Friday. The problem was just supply chain, not regulatory.

Happy Reefing.

At a time when good news seems in short supply, that is good news.