Ca reactor pH - flow rate

[flowerseller]

I'm curious how people tune their Ca reactors.

 

There is no wrong or right answer to what I'm looking for.

 

I'm interested to see how people keep;

 

pH

effluent rate flow (drip - stream)

bubble count per minute

auto controlled via controller

OR

flying by the seat of your pants

 

Feel free to answer and/or explain your reasoning as much or as little as you choose.

 

Thanks a bunch for participating

[Brian Ward]

I'm curious how people tune their Ca reactors.

 

There is no wrong or right answer to what I'm looking for.

 

I'm interested to see how people keep;

 

pH

effluent rate flow (drip - stream)

bubble count per minute

auto controlled via controller

OR

flying by the seat of your pants

 

Feel free to answer and/or explain your reasoning as much or as little as you choose.

 

Thanks a bunch for participating

 

I'm current "Seat of my pants"

I have the flow at a fast drip (was a slow stream, but adjusted down), the CO2 slow - less than 1 bubble/sec. and test frequently. I'm going to set it up in the controller, but I need some 4.00 calibration solution to set up the pH probe - otherwise I would have done it by now. I had a problem on initial set up where the reactor drove my Alk above the range of the Salifert test. Not Good. So I'm basically still tuning and I'll finalize everything once I get it on the controller.

[OUsnakebyte]

I FINALLY have mine operating!!!

 

- pH

I shoot for 6.5-6.7

 

- effluent rate flow (drip - stream)

It's just beyond drip in a stream, make sense?

 

 

- bubble count per minute

Never really paid attention to the bubble count, since there is a pH meter, but... it looks like there is 15-18 every 15 sec, so, multiplied by four, that would be 60-72 a minute. Hmmm.... that seems a bit high...?

 

 

- flying by the seat of your pants

No controller here - don't own one.

 

 

I would like to add to this survey... Has anyone ever tested the output of their reactor for Calcium? I tested mine last night for the first time, and it was ~350-360ppm. Is that about right? Anyone getting higher than that? I did this after testing the calcium in my tank, which was down to about 320ppm - too low for me, so I started adding turbo calcium again...

 

Cheers

Mike

[DaveS]

Fast drip/slow stream. Output goes to a little PVC pipe with a cap on the bottom and the pH sensor is inside there. CO2 is around 1 BPM. Controlled by AC3.

 

Other items of interest:

 

- I used to have a slower flow but realized that since the ph sensor is not bulkheaded in the reactor, the lag time would cause my pH in the reactor to drop too low. Anyone got a good tip on installing a bulkhead for the sensor in the reactor?

 

- I used to leave the output valve wide open and try to control the flow rate out of the reactor by the tap off my main return that feeds the reactor. The thought was to not have any pressure in the reactor vessel. I have since found that either my pump or the gate valve on the tap is not consistent. Over time the pressure or output would fall. This would cause little/no water to go through my reactor. Again, since the pH sensor is in the output, it wouldn't know there was no output or that the pH inside the reactor had dropped so CO2 would continue to be fed into the reactor. :( Keeping a slight positive pressure in the reactor seems to compensate for slight fluctuations in the feed strength.

[ctenophore]

I was all high tech until my pH probe quit working (not an old probe either). Now it's "seat of pants" mode. I keep my flowthrough rate very high in order to have it stay constant. I find that a slow drip flowthrough tends to vary and clog faster. Then just a matter of amount of CO2 and duration. I set a target reactor pH and a time, say 5 hrs per day at pH 6.5. Now since my probe isn't working, I just keep the same bubble rate (i.e., reactor pH) and adjust the CO2-On duration. Once I get to 24h-On, then I will fix the probe and adjust the CO2 rate.

[OUsnakebyte]

...but I need some 4.00 calibration solution to set up the pH probe - otherwise I would have done it by now.

 

Brian - I have some unopened 4 packets if you want to swing by.

 

Cheers

Mike

Edited January 30, 2009 by OUsnakebyte

[ctenophore]

- I used to have a slower flow but realized that since the ph sensor is not bulkheaded in the reactor, the lag time would cause my pH in the reactor to drop too low. Anyone got a good tip on installing a bulkhead for the sensor in the reactor?

I have probe adaptors that just need a 1/2" FPT hole in the lid. I will bring you one and a drill bit + tap tomorrow, we can install it in 15 min.

[ctenophore]

I would like to add to this survey... Has anyone ever tested the output of their reactor for Calcium? I tested mine last night for the first time, and it was ~350-360ppm. Is that about right? Anyone getting higher than that? I did this after testing the calcium in my tank, which was down to about 320ppm - too low for me, so I started adding turbo calcium again...

 

Cheers

Mike

I think we should really be calling them "Alkalinity reactors" since they add balanced amounts of Ca and CO3, which means alkalinity would shoot sky high if you attempted to bump up calcium 20ppm using a reactor. I've always used CaCl2 to set my calcium where I want it, then use the reactor to maintain both Ca and CO3

[rocko918]

Great topic Chip.

 

I have been playing with my reactor for a while now and have not gotten it to where i want it.

 

Right now it is on a drip and 1bp sec. I think i am going to change the drip to a flow and lower the bubble rate for now.

the drip falls into a tupperware with my probe and overflows into the sump.

 

It is controlled by my ac3, right now it only goes on a half hour after all lights are on and off half hour before the lights go out. I do have a few shut off statements of the ph gets too low.

[OUsnakebyte]

I think we should really be calling them "Alkalinity reactors" since they add balanced amounts of Ca and CO3, which means alkalinity would shoot sky high if you attempted to bump up calcium 20ppm using a reactor.

 

Good point.

[Gatortailale]

I found this a good read on how calcium reactor works & making adjustments

 

 

Calcium Carbonate Reactors

Sanjay Joshi: http://www.reefs.org/library/talklog/s_joshi_062997.html

 

 

Adjusting the Reactor (and some reactor Math)

Once you have decided to add a reactor, how do you go about adjusting it, i.e. determining the effluent flow rate and the amount of CO2 to be added.

 

The following discussion is based on several personal conversations with Dr. Craig Bingman, and the experience of several others in the Fishroom.

 

Let us assume that the reef system contains T liters of water. Set the CO2 flow rate to approx. 20-30 bubbles/min and the effluent flow rate to a slow enough drip and let the reactor run for several hours until it reaches a steady state. Measure the effluent flow rate in liters/hr - say its L liters/hr.

 

Now measure the alkalinity in the tank, and the alkalinity of the effluent. The difference between the two values will give you the increase in alkalinity due to the reactor. Let us say this is d meq/L.

 

Assuming no calcification and use of alkalinity, this will result in a an increase in tank alkalinity that is given by the following formula:

 

Increase in tank alk/day due to the reactor = (d x L x 24)/T - (1)

 

Now measure the tank alkalinity after a day. The difference between the increase in alkalinity due to the reactor and the actual increase in alkalinity will give you the daily consumption of alkalinity for your tank. Let us say this value is c meq/L.

 

So now we need to adjust the reactor so that the daily increase due to the reactor is approximately c meq/L. This will give us the setting at which the reactor will replenish the alkalinity that is consumed daily.

 

Looking at the equation (1), we can see that there are 2 ways in this can be achieved.

 

(1) adjusting d - the increase in effluent alkalinity

(2) increasing L - effluent flow rate

The effluent alkalinity can be increased by increasing the amount of CO2, and keeping the effluent flow rate constant. Increasing the flow rate will result in a decrease in effluent alkalinity if the CO2 flow rate is not simultaneously increased.

 

Which one of these is a better adjustment?. My opinion is that increasing the amount of CO2, and keeping the flow rate is a better choice, since it adds less CO2 to the tank.

 

Similarly to reduce the alkalinity of the effluent, it is better to reduce the amount of CO2 added.

 

I don't want to bore you all with the math and chemistry details but I feel that a basic understanding is necessary to avoid the trial and error, and test and adjust solutions. You can use the above equation to calculate, for example, what the value of d should be, given a certain effluent rate and the desired increase in alkalinity - rather than making wild guesses and adjustments.

 

---------------

 

I was using AC III to control it but I think probe need checked as I think after last calibration it was reading high. Effluent rate - I try to set at about 100 ml per min. I use B-ionic 30ml dosing cup and count 15 seconds and see where I'm at.

 

I've never tested it for calcium. I have in past tested alk to see if I'm at 20+dkh to verify its working.

 

Bubble rate - I'm probably around 80+ / min right.

[kngfisher]

I setup mine per vendor documentation....

 

I use a old baby bottle w/ ml markings on it and timed for 1 min

 

flow rate = 35ml per minute

 

ph of effluent taken by probe in lid of reactor by AC3

ph usually at 6.8 - 6.9

 

bubble is very slow....1 every 3 - 4 sec

[flowerseller]

Thought I'd add a Link to CMAS's responses.

 

I got several PM's and

Mine is as follows.

 

I shoot for pH of 6.85-6.89 via ACIII

My effluent rate is a slight stream *

Bubble count (solenoid) is controlled via ACIII but = 1bps when "Open"

 

* This is my experiences with my current DIY "all internal" reactor which I love.

 

I feel more comfortable with a faster, less potent, effluent rate.

Less chance of a fast run up in ALK, my main reason for the Ca reactor, oddly, not for the Ca content.

lower ALK and lower Ca.

The higher the internal pH in the reactor, the lower levels you'll likely achieve.

If the internal pH is too low, you are due to have the media mush on you, even with the coarser sized medias. While I find they provide better flow, I also find they can also allow channeling and provide more places for bubble pockets to form.

I check my ALK weekly and my CA bi weekly and adjust it with either, Kent turbo or Seachem.

I can not for the life of me keep a MG level above 1150 for long.

I also know I'm currently using 1.5dkh per day based upon down time testing, this is down from 2+ when I had all my big colonies and 17" clam.

[Origami]

pH

effluent rate flow (drip - stream)

bubble count per minute

auto controlled via controller

OR

flying by the seat of your pants

 

Feel free to answer and/or explain your reasoning as much or as little as you choose.

 

I'm a newb with Ca reactors. I run both a reactor and a kalk stirrer. The Ca reactor is pretty much set up to the mfr baseline and my levels seem to be staying pretty well where I want them (alk 10, Ca 430)

 

Internal pH is kept between 6.6 and 6.65 (I modded my Korallin c4002 for an internal pH probe using a 1/2 inch In-Line Probe Mounting Gland w/ Compression Fitting that you can get at Marine Depot)

Tank pH hovers around 8.1

drip effluent - 25 drips per min

bubble count 12 per min when on

Controlled using an AC III.

 

Since my Ca and alk are staying about where I want them, I figure that my settings don't need further tuning, though I am in the process of using the AC III log data to find ways to stabilize my pH and temperature cycles (I just put my frag tank on a reverse light cycle with my fuge, for example, which should have some impact on temp and pH stability.).

Edited January 30, 2009 by Origami2547

[SteveM]

pH

I keep mine between 6.47 - 6.53

 

effluent rate flo

A steady stream (Or you could say a very fast drip)

 

bubble count per minute

Have no idea - I don't have a bubble counter. My guess would be about 1 per sec

 

auto controlled via controller

I run it with my ACIII, thats why I dont worry about the bubble count. Ph goes down the ACIII kicks the CO2 on, Ph goes up, it kicks the CO2 off

 

I have it dialed in pretty good. I have a very consistent Alk and Cal reading every month.

[Origami]

I would like to add to this survey... Has anyone ever tested the output of their reactor for Calcium? I tested mine last night for the first time, and it was ~350-360ppm. Is that about right? Anyone getting higher than that? I did this after testing the calcium in my tank, which was down to about 320ppm - too low for me, so I started adding turbo calcium again...

 

I've not checked my calcium, but I have checked the alk of my effluent: It's 40 dKH.

 

Working the math: Since I try to maintain my water at 10 dKH (3.6 meq/l), the calcium reactor adds 30 dKH (or 10.7 meq/l) to the effluent (output alk = input alk + what the reactor adds). Since 1 meq/l balances with 20 ppm of calcium in the formation of (or in this case, the dissolution of) coral skeleton, that implies that the reactor adds 214 ppm of calcium to the effluent. And, finally, since I try to maintain my calcium levels in my tank at 430 ppm Ca (input calcium), this would put my effluent at 644 ppm. Mathematically speaking, of course.

[Origami]

Anyone got a good tip on installing a bulkhead for the sensor in the reactor?

 

Search "Probe Mounting Gland" at Marine Depot and you'll find the right solution. It's a threaded fitting, so you need to drill and tap the lid of your reactor. (I've got a drill and tap if you need a hand.)

[DJBoy98]

For those with AC3/jr to control the PH of the Ca reactor, how often does the controller open and closes the solenoid?

 

For me, it takes about 4 minutes to open then shut at a range of 6.65 to 6.53. I don't want to wear down the solenoid but I

want to see what's the norm.

[ctenophore]

Try to set your bubble rate close to your target so the solenoid doesn't have to open and close as often. You should be able to get it to about once every 30 min to 1 hr with some tuning.

[flowerseller]

I don't think there really is a norm.

I find the solenoid will open and close depending on the effluent flow thru rate.

More often if the rate is faster since it takes less time to change the internal pH of the reactor.

[DJBoy98]

I dailed it down to about 2 and half minutes before it drops .1 PH reading. This will get me to about 45 mins before it opens and shuts. My drip rate is

a fast drip. I think my Eff Alk reading is around 20-25 dkh. Hopefully this will raise my alk to around 10 and 430 ca.

 

Oh the joys of tuning...

[dschflier]

Great thread. I am glad I found it and will read the other connecting threads as well. I hope this isn't considerd hijacking a thread. I figure it wasn't being used anyway. I have been considering starting up my calcium reactor for a long time and have just been chicken to do it. I finally feel within the next couple of days I am going to. I have a AC2 but will not be using it initially and will be getting PH probes but will not be using them initially either.

 

do you think it is safe to check my PH and Alkalinity before I begin. Start adding Co2 and a drip rate of 1drip per sec and a flow rate double that. I have a marine technical concepts reactor which looks like this

 

I am also curious if anyone on the board here has used one of these before. I am not sure what the red tubing is for. I dont think the reactor has a place to put a PH probe but I might be wrong.

 

One more question I have never used the regulator and solenoid. Does the first control open all the way up and the second one controls the drip rate?

 

Any insight is appreciated.

Edited April 26, 2009 by dschflier

[dandy7200]

I haven't measured in a LONG time I now look at the reactor and make sure it is dissolving about 5#/month. since I know my reactor holds 30# of media it should be refilled about every 4 months with another 20# of media. Reactor is set at 6.6 and flow is pretty fast (whatever that means :P ). Milliporas retract polyps and start lightly bleaching in a unusual pattern when alk is low, I've never really had a problem with alk being too high since my rock eats pretty much everything I throw at em.

 

So I guess my answer is:

 

pH

effluent rate flow (drip - stream)

 

auto controlled via controller

AND

flying by the seat of your pants

AND

observing health of corals with known visual indicators of water chemistry

[overklok]

I flow about 50 drops a minute and inject 40 bubbles a minute of CO2.