Anyone using Schuran or Gen-x large media in their calcium reactors?
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When I get my system up and running, I'll be using this in my schuran ractor. I've read alot about it and it seems like it's useful to run in a large system, namely becuase you can lower the pH in the reactor to the low 6 range and you don't end up with melted media like you would with ARM. I've read a long schuran thread where the poster was running effluent that was 50-60 dkh, though he only ran it around 6hrs a day in 1.5hr intervals to avoid depressing the pH in his tank. What kind of reactor are you going to be running?
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Mike:
I read of people switching from ARM to Shuran or others, but the logic was a bit dubious to me. They made the claim that the shuran did not "mud" as much as the ARM. From what I understand, when the media "muds", it is due to set up problems, not media problems. When the pH gets too low, the media excessively dissolves and becaomes unstable and mushy. However, if pH is controlled, it should be fine. Shuran and ARM both are meant to be operated at the same pH (as far as I can discern), so I dont see how one could operate any differently under the same parameters.
I know Shuran has larger pieces, so it would channel less if debris is introduced into the media, but this will also reduce surface area.
Personally, I'll save my money, and stick with ARM, unless someone can come up with a good reason to switch.
I read of people switching from ARM to Shuran or others, but the logic was a bit dubious to me. They made the claim that the shuran did not "mud" as much as the ARM. From what I understand, when the media "muds", it is due to set up problems, not media problems. When the pH gets too low, the media excessively dissolves and becaomes unstable and mushy. However, if pH is controlled, it should be fine. Shuran and ARM both are meant to be operated at the same pH (as far as I can discern), so I dont see how one could operate any differently under the same parameters.
I know Shuran has larger pieces, so it would channel less if debris is introduced into the media, but this will also reduce surface area.
Personally, I'll save my money, and stick with ARM, unless someone can come up with a good reason to switch.
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well, jesse posted a comment along what I was talking about. Jesse, where is this thread? I would like to find out where it says to run the media at a pH of 6.
Just found the link: http://reefcentral.com/forums/showthread.php?s=&threadid=397189">http://reefcentral.com/forums/showthread.php?s=&threadid=397189</a>
Now this was particular to a schuran reactor, but the idea was that the company boasts of being able to completely dissolve the contents of the chamber in a month. I don't think the effluent pH was as low as 6, but in the low 6's
Now this was particular to a schuran reactor, but the idea was that the company boasts of being able to completely dissolve the contents of the chamber in a month. I don't think the effluent pH was as low as 6, but in the low 6's
I haven't had my media turn to mush but I do end up "wasting" some when it's time to refill the reactor. I end up cleaning out whatevers left in the reactor and filling it with new media. It appears as if that would be alleviated using the larger media. The primary reason though I was thinking of switching was to try and combat the channeling that occurs on occasion in larger reactors. I was also thinking that it might not put as much stress on the recirculating pump as well since there wouldn't be any compaction of the media. I'm currently using ARM with some dolomite and it's worked well but am getting ready to start up a much larger reactor so I thought I'd see what others were doing.
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Interesting thread. Here is what I dont understand about this "overloading" principle. Apparently, you can run this reactor at slightly lower pH's (6.2-6.5) than most calcium reactors (which should run 6.5-6.8 ish, but not below 6.5). Personally, I dont think there is much validity to this claim, as media like ARM is likely made of the exact same material as the Shuran- coral skeleton. The ARM is just in smaller pieces. So, what makes it withstand the mentioned lower pH? The only thing I can guess, it that the larger size masks the dissolution better. It doesn't necessarily tolerate the lower pH better. That being said, this will prevent channeling better, which seems to be a main concern. But, why run the lower pH? If you want to boost the alkalinity, decrease the effluent rate. If you cant or dont want to do that, increase the CO2. If that drops the pH, increase the effluent. There is adjustment to all these scenarios with any reactor. I can go through a canister of media in a month too, if I wanted my effluent to be 80 dkh, or whatever it was. That seems like a ridiculous number, but if I pump my needle valve to put out 50 bubbles a second, and my effluent rate like 300 ml/min, I would probably hit it, without my effluent pH going below 6.5. But again, I ask, why?
Here is the only benefit I can see to the Shuran media- it will allow you to be more sloppy with your CO2 adjustment. But the cost of this will be more imprecise long term operation. The larger media will not dissolve as quickly or readily as the smaller, as it has less surface area exposed to the acidic water in the chamber (which is why it is more tolerant).
I personally run a MRC CR-2 with a spray bar and ARM media, and it resolves many of the issues desribed. The spray bar minimalizes any channeling if it were to occur. With my effluent pH at about 6.6, my effluent rate at about 75 ml/min, and my effluent alk at about 10 dkh, you can't convince me how a different media would be better.
Just my opinion.
Mike- another people have mentioned for reducing channeling is making the creactor chamber go upflow, rather than downflow. I cant comment on it's effectiveness, just something I've heard.
Here is the only benefit I can see to the Shuran media- it will allow you to be more sloppy with your CO2 adjustment. But the cost of this will be more imprecise long term operation. The larger media will not dissolve as quickly or readily as the smaller, as it has less surface area exposed to the acidic water in the chamber (which is why it is more tolerant).
I personally run a MRC CR-2 with a spray bar and ARM media, and it resolves many of the issues desribed. The spray bar minimalizes any channeling if it were to occur. With my effluent pH at about 6.6, my effluent rate at about 75 ml/min, and my effluent alk at about 10 dkh, you can't convince me how a different media would be better.
Just my opinion.
Mike- another people have mentioned for reducing channeling is making the creactor chamber go upflow, rather than downflow. I cant comment on it's effectiveness, just something I've heard.
ARM is not the same as Schuran, ARM is bascially calcium carbonate. Schuran is a full coral skeleton, which to break mit down requires a lower PH. I can't remember what the compound is called. That is why ARM melts at a higher PH. I myself am using a MRC-2R reactor with a spraybar upgrade. It could not keep a low enough PH to melt my Korallith Media. I had to mod it to keep up with my 300 gallon system. I now do not waste CO2 and achieve a PH of 6.7 out of the second chamber, but it looks like it is maintaining my cal and alk. ARM would liquefy at the PH I keep in the first chamber.
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How do you figure? What is the difference?
What modification what needed to reduce pH on the CR-2? I am curious, because what you are claiming debunks my understanding of how reactors work. From what I understand, if your pH out of the second chamber is 6.7, then it would be like around 6 in the first. Why do you need to keep it so low?
I'm not sure this is the mod he's referring to but it is a helpful one none-the-less...
(gasp! ARC president referencing another forums content!!!)
http://reefcentral.com/forums/showthread.php?s=&threadid=63481">http://reefcentral.com/forums/showthread.php?s=&threadid=63481</a>
I plan to implement this mod the next time I do a refill on media (too much of a pain to take it all apart for one reason...lol, I'm so lazy sometimes)
(gasp! ARC president referencing another forums content!!!)
http://reefcentral.com/forums/showthread.php?s=&threadid=63481">http://reefcentral.com/forums/showthread.php?s=&threadid=63481</a>
I plan to implement this mod the next time I do a refill on media (too much of a pain to take it all apart for one reason...lol, I'm so lazy sometimes)
I did the same exact idea on my MR-2, as the thread but the MR2 is not enough of a reactor to keep up with a 300 gallon system. It should at least be an upflow design on both chamber with the recicrulation design from the 2nd chamber like mine, this captures any escaping CO2 but also lets some water recirculate a 2nd time which it needs to lower the KH coming out.
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I still dont understand why you are trying to melt your media. I dont doubt it is hard to abuse- because of the reasons I mentioned. Less surface area = less exposure = less severe results. Coral skeleton is made of up calcium carbonate, so crushed calcium carbonate is no different than the larger "chunk" media, it just has been mechanically broken to increase surface area.
I cant comment on the capacity of the CR-2 reactor on a 300 gallon tank. But I dont see how media can help you any. If you need a higher alkalinity, why couldn't you speed up the effluent rate, and also speed up the CO2 input? Or mod the recirc CO2 as you mentioned (which, by the way, is really slick)? I dont have any data to back it up, but the outward physics of the matter is that a lower pH over less a surface area would problem be equitable to a higher pH over a larger surface area.
Maybe I am not seeing something here. But can anyone explain why they need to run there calcium reactors at lower pH's?
I cant comment on the capacity of the CR-2 reactor on a 300 gallon tank. But I dont see how media can help you any. If you need a higher alkalinity, why couldn't you speed up the effluent rate, and also speed up the CO2 input? Or mod the recirc CO2 as you mentioned (which, by the way, is really slick)? I dont have any data to back it up, but the outward physics of the matter is that a lower pH over less a surface area would problem be equitable to a higher pH over a larger surface area.
Maybe I am not seeing something here. But can anyone explain why they need to run there calcium reactors at lower pH's?
I do not know the makeup of a coral skeleton, I just do know that Arm would turn to mush under the conditions that I am running it at. Korallith is calcium carbonate, Schuran, Gen-X which are coral skeletons is listed as a different product, not just calcium carbonate totally. I wish i had more time to research this, but Marine Depot told me the difference between the two and that a lower PH is necessary to dissolve a natural coral skeleton. Calcium carbonate may actually be a mined product, or a byproduct from dredging I am not sure. I have run ARM for the last 3 years in a Korallin 1502 ands upgraded when I changed tanks to my MRC2. To increase KH, the effluent must stay in contact with the media longer, to allow the effluent to be satuarated up to a certain point, I am already forcing in as much CO2 as possible in the reactor, before the recirculating mod is taking over. I am more than willing to let anybody take a look at it to try to help me if it is possible. But physically I am not sure if it is possible.
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I guess I can add a little more to this. Coral skeleton is made of calcium carbonate. In fact, the vast majority of reactors use calcium carbonate in them as the media, in whatever shape or form. Some people add some things for additional boosts (as mufret is doing with the dolomite). So making a comparison of coral skeleton with calcium carbonate is kinda comapring the same thing to itself. The only real differnce I can attest to is the size of the object. Crushed coral (the calium carbonate of ARM), is just that, crushed coral. The Shuran, etc. coral skeleton media, is just bigger pieces. I dont know what Marine Depot told you, but to me it sounds like a sales pitch. I am speculating, so I could (and likely) am WAY OFF. The reason it can "tolerate" a lower pH is not because it is a different compound, but because it is bigger and has more integrity. It dissolves equally as the ARM, but since the ARM pieces are smaller, they have less mass left, and give the appearance of "mush". A larger object will dissolve, but is still substantial, so it won't look like "mush". Quite actually, the ARM with have better dissolution, because it has more surface area in contact with the reaction water. To make an analogy, what happens if you put a giant ice cube in your drink? It takes forever to melt, and takes a long time to cool the drink. What about the same volume of ice chips? They melt, but a lot quicker, and with a lot more effectiveness. What about the in between, normal sized ice cubes? They land in the middle. This is due to surface area exposure, not anything to do with the composition of ice. This same overall process applies in what we're talking about.
In terms of running your calcium reactor, I do think there is a way to increase alkalinity without lowering the effluent pH. As generalizations, when you increase the CO2, alk increases (and pH drops). When you decrease effluent rate, the alk increases. So, if you increase the Co2, and increase the effluent rate to combat the pH drop, you will be adding more alkalinity. 2 bubbles per second is not at all the upper limit. Tom Wyatt told me he ran a tank with 45 bubbles per second! His effluent rate was likely also very high.
Overall, I am certainly not debating whether Shuran works, or has benefits. But I do not see how it can be better than other high quality media, as described. Just my opinion.
I wonder if this explains, why ARM says it has more strontium than others? Maybe it is from a different ocean or a different place, say that ARM comes from Florida and Schuran comes from Fiji? Slightly differnet makeuhttp://www.livescience.com/animalworld/060707_coral_change.htmlp.
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The link wouldn't work for me.
But, what you said is very true, Gulf Coast areas are supposed by be very very high in aragonite and purports more strontium. But this will not change the biochemical nature of them. Nothing more or less is needed to dissolve Atlantic calcium carbonate than Pacific calcium carbonate.
In thinking more, I do not to also make some confessions to my previous comments. I have claimed that the ARM more actually have a slight benefit over larger sized media due to greater surface area and contact- this only works under the presumption that the smaller ARM media is not channelled. If the media has compacted, I cannot make this claim. Another thing to make claim- I have noticed that there is a alot of "debris" in the ARM (gorgonian branches, bivalve shell, etc.). Which this will not necessarily alter the biochhemical method of dissolution, it can (and potentially will), add unwanted things to the water (such as phosphates, or possibly worse things). For this reason, I like the large coral pieces a little better (there is smaller potential for contamination).
KH971- I hope you did not take my objection as a slight on your setup or technique- actually quite the opposite. I just have heard far too often the claim that such media works "better", and I have yet to hear why. It may be safer, cleaner, more negligent forgiving- but I cannot say better. I still feel a properly tuned reactor with ARM can and will outperform one with the large coral pieces.
Yes you are righ that ARM would be more efficent, I am definelty a bliever now. We alwys here about the BETTER and newest way to makeour corals grow faster or make them more colorful, not always true, nor are some of the answers for some people with certain systems. Day in day out nothing is better for a tank other than doing regular water changes.
No, I did not take objection, the link was quite interesting , it was saying how corals took in differnet amounts of magnesium, or calcite or strontium to make their exoskeleton out of.
Now here's another question, I assume the polyp use the magnesium to aid in calcification? That or we should never have to add magnesium to a tank that runs a reactor. Since we are replacing in the same proportions, dissolving old corals to make new ones. I am not sure, do you know?
No, I did not take objection, the link was quite interesting , it was saying how corals took in differnet amounts of magnesium, or calcite or strontium to make their exoskeleton out of.
Now here's another question, I assume the polyp use the magnesium to aid in calcification? That or we should never have to add magnesium to a tank that runs a reactor. Since we are replacing in the same proportions, dissolving old corals to make new ones. I am not sure, do you know?
The issues debated here are the same ones that I've found in my research. My thoughts of switching to the larger media was not that the ARM media wasn't working. I've actually had quite a bit of success using it. My thoughts, as I moved to a larger reactor, was to try and minimize channeling as well as minimize the "leftovers" that I tend to get using ARM. As jmaneyapanda pointed out, some of this is probably due to the debris that is often found in the ARM media. I think the larger media has some benefits in that regard and will probably try it. I don't however think it's necessary to run a reactor at super low Ph levels to use the larger media, it will just handle the lower Ph levels better than the smaller media.
kh971 - the dolomite that I add to my reactor helps in keeping my magnesium where it needs to be. I do still test, and add magnesium when needed, but the dolomite makes it much easier to keep the magnesium levels stable.
kh971 - the dolomite that I add to my reactor helps in keeping my magnesium where it needs to be. I do still test, and add magnesium when needed, but the dolomite makes it much easier to keep the magnesium levels stable.
