Dual stage Ca++ reactors...overrated?

[fudge1]

Hi all,

Im beggining to think that they are not all they are claimed to be,

While i do agree there is benifits to them,i am wondering if they warrant a purchase of a second chamber.
Since running one,ive noticed there is much less dissolving of the media in the second chamber,becuase of the increased ph,sort of defeating its purpose IMO.

Wouldnt it make more sense to have a larger capacity single stage,so PH is consistent with only one body of water?
With co2 dissolving the same amount of media in a single pass?...(able to leap small buildings in a single bound?

)

Your thoughts?

Thanks,Marc

[ August 13, 2001: Message edited by: fudge ]

 

[SPC]

Hi Mark, I am trying to learn about Calc reactors before I make a purchase so find this subject of interest to me. My understanding was one of the main functions of the second chamber was to raise PH before it is returned to the tank. Now, my question is if there is not much Calc dissolution going on in the second chamber, could that chambers main function be used to drive the co2 off and get the PH back up?
Steve

 

[mweber]

I added the second stage to my DIY. The advantage I see is that the end resultant PH is much higher thus not lowering your tank PH. What I did could be added to any single stage reactor. I put a butter dish with holes in it in the bottom of a 1 gal pitcher. I hang the pitcher on the side of my sump. I run my calc reactor effluent into the butter dish which slowly distributes it through the oolitic that fills the pitcher to within 1" of the top.

 

[XXX]

Marc,

I have a Korallin 1501 and a Geo 2nd stage. My initial reason for going this route was hoping it would boost my tank pH some. It didn't. But I still think it has been a benefit overall.

Yes, there could be less dissolving in the second chamber because of a higher pH there. So I use Corallith media in chamber 1 and ARM, which dissolve at up to 7.5 in chamber 2. Maybe there isn't any difference in what additions you get out of the two medias, but maybe there is some. I like using the two medias for this reason. You could just mix the two in one large chamber, but this method seems to work well for me. I don't think whether the media in seperate chambers dissolves at the same rate or not really make much difference in the long run. Unless there is something in that area I am unaware of. What do you think?

Another thing in my case would be placement of the reactor. In my cramped under the tank setup, I can make the two smaller chambers fit better around the rest of my equipment than one large chamber.

Steve

 

[fudge1]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>
Originally posted by Nathan:
<STRONG>What we need is to conduct SCIENTIFIC EXPERIMENTS using calcium reactors to make accurate determinations. </STRONG><HR></BLOCKQUOTE>

Well it wont be scientific,but i have built a large reactor(chamber easily holds the same amount of media as a dual chamber)
I will place the same amount of media as i have in my dual stage and a similar amount of co2,and replace the dual stage with it.
I will post the results.

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Nathan:
<STRONG>
It is at this point that your reactor is running with the maximum efficiency. This is the point at which the effluent has the least amount of CO2/ml/min and the most CaCO3/ml/min.</STRONG><HR></BLOCKQUOTE>

I agree,but only as efficient as a "Second chamber" can be....wouldnt the same amount of media dissolve more efficiently and faster if the whole body of water was at the proper ph?

My concern with this is obviously co2 is not making it into the second chamber...or the ph would be identical.

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR><STRONG>
Also, even if you had the largest calcium reactor, it would still make sense to run the effluent through a "2nd" chamber. This helps to make use of any extra CO2 that is available in the effluent.
</STRONG><HR></BLOCKQUOTE>

But if that is its main function,why not just drip single chambers effluent in the intake of a skimmer,or the like?
the results are still a decrease in alk,and a rise in ph.


Maybe if i could get those of you with different dual chambers to answer a question:

Do you find that when reactor is running at full (co2) volume,co2 is escaping from the effluent from the second chamber?or will it pool up in the first chamber...requiring you to "bleed" it?


I think it just may be that i suffer from "current set up sucks" syndrome.

Thanks for all your input guys,Marc.

 

[KenH]

Here is my input.

I have a large single-stage reactor (PM CR622) which holds about 15lbs of media. I built a second stage to play with the cause and effect. In my case, I primarily was wanting to raise the pH of the effluent to help raise the pH of my tank overall.

The second stage is a simple 4" acrylic tube that is about 20" long and filled with ARM media. A thin acrylic tube down the center accepts the output of my reactor and releases it at the bottom of this tube where it filters up through the 4" tube filled with ARM and out a hole toward the top of the tube. The setup does not allow CO2 to enter the 2nd chamber, so there is no build up there.

Here is a pic of the 2nd chamber by itself and sitting in my sump.

My observation is that it did raise the pH of the effluent about 6.8 to 7.3 on the day I checked it which is pretty significant. I don't know if other designs are more efficient or not in this regard. Surprisingly the pH of the tank did not move until I added an airstone to the sump. I keep meaning to remove the airstone temporarily and see how much effect the 2nd stage is adding vs. the airstone. My gut feel is that the 2nd stage has had less affect than I would have thought.

--- Ken

 

[Minh Nguyen]

I think the second chamber is use to recover any excess CO2 that is not disolved. It will stay in the second chambe and disolve in solution when the solution is not 100%saturated.
In the single chamber, these CO2 just excapes out with reactor out-put. The second chamber help Ca reactor be more efficient with CO2 usage and also have more volume for CaCO3. If adjust correctly, with the second chamber, there is no wasting of CO2 like in a single chamber reactor.

 

[fudge1]

Thanks guy`s,

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Minh Nguyen:
<STRONG>In the single chamber, these CO2 just excapes out with reactor out-put.</STRONG><HR></BLOCKQUOTE>

I agree Minh,but what if theres twice as much media (in hieght)in the chamber,then co2 has double the saturation time for only a single pass through the reactor?


Anyways,i guess the difference would only be those who need the second chamber to raise PH,or wether they need them to actually replenish more CaC03.(and maybe double C02 life?)

Just thinking out loud,Marc.

 

[Ritteri&amp;Bubbles]

KenH: I think your PH test kit is caput!

If your 2nd reaction chamber was reading 7.3 then you're not dissolving any media at all, the PH must be acidic for the media to break down. Up here in the sticks we also had a debate over the worth of a 2nd chamber, which I find to only add capacitance to a tanks Cacium requirements. But a slow effluent drip coming out of a cacium reactor whether its 6.4,6.6,6.8, or 6.whatever is not going to make any noticeable difference whatsoever to a large volume of water in your main tank. In other words, your PH in your main tank will not change whether u use 1 chamber with an effluent drip at say 6.5 ph to using a duel chamber that may rise that ph to say 6.8 or 6.9. The volume of water coming out of your reactor is very minimal and only ml's per day. If you're going to add a 2nd chamber, the only reason to do so would be to add media volume to keep up with calcium demands. Just like your tank size, the same goes for Ca reactors, got a larger tank? Get a larger reactor. I too use a PM CR622, works great, it runs both my 120g and my 150g simultaneously.

One last note: If you're worried about your ph being suppressed, then all you have to do is raise the drip line up higher so that the CO2 dissipates into the air before it reaches the sump.

[ August 13, 2001: Message edited by: Ritteri&Bubbles ]

 

[M.E.Milz]

Well, I would like to do some thinking out loud as well. I have a Koralin 1501 that I have been using for about a year. Some time ago, I added a simple second chamber by filling a Tap Water Purifier (TWP) with media, with the effluent entering the bottom and exiting the top of the TWP. I saw very little (if any) disolving of the media in the TWP, so I finally removed it.

However, perhaps I did not have the 2nd chamber set-up correctly. For example, the Koralin reactor has 2 outputs, one that traps CO2 in the reactor and one that allows the CO2 to escape with the effluent. I use the first output. That means that no CO2 is allowed to enter the 2nd chamber. Thus, the only dissolution of the media will be the result of the lowered Ph of the effluent. I think that this would be similar to dripping the effluent through an open container of media.

However, if I were to switch outlets, then some (or as much as I want) CO2 will escape and enter the 2nd chamber (i.e., so that it percolates up through the TWP). This may actually help increase the dissolution of the media in the 2nd chamber.

As far as allowing CO2 to escape into my sump, I suppose that I could use the hole in the top of the TWP as a vent hole and draw the effluent from an extra hole drilled a little below the top of the TWP. Of course, this would only work if this extra hole is above my sump (so that the effluent will drip by gravity into my sump). This would be similar to KenH's design (assuming his chamber has an open top).

Any thoughts or comments?

 

[fudge1]

One more,if i could

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by fudge:
<STRONG>


Maybe if i could get those of you with different(diy or w.h.y) dual chambers to give me some info:

Do you find that when reactor is running at full (co2) volume,co2 is escaping from the effluent from the second chamber?or will it pool up in the first chamber...requiring you to "bleed" it?


</STRONG><HR></BLOCKQUOTE>
Marc.

[ August 13, 2001: Message edited by: fudge ]

 

[KenH]

Ritteri&Bubbles,
I don't think it's my pH meter thats Kaput! It was taken with a brand new,newly calibrated Pinpoint monitor. I took another look at the number I wrote and it does not look right to me either. I took it off my website, but must have a typo in there. I will recheck the delta between the stages when I get home. Seems to me like I was seeing about a .2 shift in pH between the stages when I have looked at it. I currently see about 6.6 out of the main reactor and I think about 6.8 out of the second stage, but I'll double-check that.

As far as your comment about only using ml of effluent a day, I would guess I am using more like many gallons of effluent a day, not ml per PM recommendation to adjust effluent output to a broken stream.

One reason I built the second stage was also to increase my available calcium since I have a fairly high demand system. The last thing I wanted to do was dump big $ on a CR and have to turn around and still supplement like many people with undersize reactors have to do.

M.E.Milz, My second stage is pretty much sealed, but the effluent is basically dripped into this stage to allow any excess CO2 to escape.

My biggest change in tank pH seemed to coincide with putting an airstone in the sump where my effluent was entering. Doesn't make sense to me since I have a PM Bullet 2 skimmer pumping huge amounts of air through the water in the sump, but that was the case. I tried having the drip line high and that didn't seem to help much.

--- Ken

 

[Ritteri&amp;Bubbles]

KenH: If you are running gallons per day, then all i can think of is a huge tank. My Ca Reactor runs 2 large tanks(at least to me!)and I probably run maybe 2 gallons per day total, and this is for over 300 gallons plus, its still nothing more than a fast drip at best, still with a 2nd chamber it wont affect your ph in your main tank anything noticeable as per using a single stage. But it sounds like to me that you have to slow your drip down and raise your CO2 usage up a bit, what size tank do you have, a 622 will easily handle 500g's + without a sweat, it holds 16 lbs of media for God's sake!

 

[Nathan1]

What we need is to conduct SCIENTIFIC EXPERIMENTS using calcium reactors to make accurate determinations.

Here is my theory based on my experience:

At any given bubble count there is an optimal flow rate through the reactor which results in the maximum amount of dissolving.

It is at this point that your reactor is running with the maximum efficiency. This is the point at which the effluent has the least amount of CO2/ml/min and the most CaCO3/ml/min.

Also, even if you had the largest calcium reactor, it would still make sense to run the effluent through a "2nd" chamber. This helps to make use of any extra CO2 that is available in the effluent.

Just thinking out loud.

-Nathan

[ August 13, 2001: Message edited by: Nathan ]

 

[KenH]

I double-checked and my second stage is raising my pH by about 0.2. My main reactor output is 6.6 and my second stage output is 6.8.

Ritteri&Bubbles,

Most people I know run effluent rates of somewhere between about 20-80ml/minute. That amounts to about 8-32 gallons a day give or take. My output is set at about 60-80ml/minute. My tank is a 225 with mostly SPS corals. I personally go more by CO2 bubble count/minute more than effluent rate. With this effluent rate and a bubble rate of about 100/minute, my tank is maintained at about 4meq/l alkalinity and 500ppm calcium. If I were to go to a slower effluent rate and increase my CO2, would there be some benefit?

I assume your tank calcium demands must be fairly low. What type of livestock do you keep in your two tanks? Also, I'd be interested in what amount of CO2 are you using by comparison.

--- Ken

 

[Ritteri&amp;Bubbles]

KenH: Actually Ken, I probably have a huge Calcium demand in my tanks, between the 2 I have multiple clams(more than a dozen)and LPS corals(many hammers,galaxies,torches,frogspawn etc)along with the intake from calcerous algae and sponges, if I dump the Ca reactor my tank is capable of dropping 100ppm in a weeks time with no sweat. Since we use the same Reactor, this may or may not benefit you but I raise the CO2 bubble count and slow my drip down, this way I have a higher concentrate of calcium in the effluent. Basically i rnu the effluents parameters at about 700ppm on calcium, and 40dkh, with a ph of about 6.5-6.4, i go through media a bit quicker this way, but the balance on my tank is rock solid, Since i do have over 2200 watts between both tanks for photosynthesis, my ph tends to want to stay high during the day(Its always an even 8.4)and during the night it goes no lower than 8.2)without the Ca reactor it would be a few points higher for sure, after trying the 2nd reactor i found no difference in my main tanks ph and had more clutter than I wanted in the sump area, thus the 2nd chamber now sits in the basement, I just ended up getting a larger single chamber unit(CR 622),the 2nd chambers ph was about .2 points higher but as something to buffer ph I found it useless. I drip prbably about 50 ml per minute, so on the earlier comment my mistake but the point was the drip is too slow regardless in too long of a time(the 2nd reactor vs. the first reactor)for a .2 ph swing to make a difference in the main tank, we are talking about a maximum ratio of 5-25 gallons to 225-250 gallons of water here dripped over a 24 hour time frame. A digital ph monitor properly calibrated might see a .009-.01 swing at best theoretically over that same 24 hour period, is this really worth it?? Not really in my point of view, if your adding a 2nd chamber to help with the bioload then yeah then it may be the proper thing, but this is why i would rather just get a larger main reactor instead.

 

[-JB]

Hey guys, you might want to check out this thread Early Results Of Added Second Reactor Chamber before continuing. This same subject was discussed in detail on Reef Central a few months back. I'm sure we can add to it, but it might help to give it a good read so we don't rehash some of the same concepts.

 

[DK]

I feel as if I am missing something. I have found that my ph has increased in my system to the extent that it never goes below 8.35 and will go above 8.5 at the end of the day (but not always). Who gives a ###fsdsdaX what the ph is of the output which is theoretically being "dripped" back into the system if the end result is a higher and stable ph for the system???

I suppose if you had a 10G tank this would be significant but would you use a ca reactor for that size tank????????????

So, ultimately, 1 stage or 2 really doesn't matter all that much.

 

[KenH]

JB, thanks for the link, good info. Course if we didn't rehash topics in this hobby that have already been discussed before, what would we talk about?

Consensus seems to be (if I may be so bold) that:

1) Although a second stage can increase the pH of the effluent within limits, it has a fairly inconsequential affect on the pH of the tank as a whole and
2) Although the second stage does increase the alk/calcium levels of the effluent, this is probably only relevant in the situation where the reactor is marginal in meeting the demands of the tank.

--- Ken

 

[M.E.Milz]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote

2) Although the second stage does increase the alk/calcium levels of the effluent, this is probably only relevant in the situation where the reactor is marginal in meeting the demands of the tank.

Well, that is my goal - my reactor (a Koralin 1501) just can't seem to keep up, and I need some way of boosting output until I can afford to get a bigger reactor.

By the way, any thoughts on how the PM CR622 compares to the new Koralin 4001, which purportedly holds 13 kilograms of media?