:) Cheapskate friendly Calc reactor :)

[liveforphysics]

I had quite a few PM's with people interested in super cheap calc reactors.

I wanted to be certian this worked well before I made a post about it. Even so, I should make some disclaimer (perticularly about useing the medium I use). Essentially, I think if you dont feel like you have a solid grasp of how a calc reactor functions, then you should skip this one.

So, first, lets get an idea what our goal is. Out tanks use Ca+ ions and CO3- ions for many different things. Argonite sand and rock does a pretty darn good job of this, however, to boost them for long periods of time above 400ppm, it takes a little something-something if you know what I mean.

So, there are a many different ways to do this. Some people dose kalkwasser and/or add 2 part liquid or powder additives. This stuff works, its just sorta a PITA and can easily be screwed up with the ballence between CO3 and Ca. When the ballence is upset, you get snowstorms in the tank and a few other undesireable things are possible as well. Im sure I dont have to tell this to you guys, as we all hear posts related to it all the time.

So, enter the calc reactor useing CaCO3 (calcium carbonate AKA white marble). Ok, so its a simple idea. We want both parts of CaCO3 in our tanks, but unfortunately, it doesnt give it up in our tanks pH ranges. This is why simply adding marble chips to the tank wont help us any. However, you put these marble chips in an enviroment with the pH around 6.5ish, and kindly gives up its Ca+ ions as it disolves in the slighly acid solution. So, now you're thinking, ok great, acid, how great, acid doesnt sound very reef friendly. Fortunately, we have this really neato acid called carbonic acid H2CO3. Unlike many other acids, carbonic acid (soda water) decomposes into good ol CO2 and H20 when left under standard pressure and temp (think of the soda you left on the counter overnight and was flat by morning). This makes carbonic acid a very safe sort of acid for our purposes. We are also in luck because it has a very simple synthisis by simply disolveing CO2 into water. This means its very simple to create controled amounts of it, which is exactly what we need.

So, for a simplified rough theroy of operation, imagine we take a gallon or two of tank water and set it aside. Now imagine we dump in pleanty of marble chips into this tank water. Now imagine we bubble CO2 into this solution untill we lower the pH to the point its able to disolve the marble chips. Now we have this low pH solution rich with calcium. This is the point which a typical reactor drips this solution into the tank. A calc reactor makes this process all automatic and neato, but this should help you understand the idea behind whats going on.



So, basicially, you just need a container with a very slow drip into it , and an overflow ability, circulation in the chamber, and a CO2 source and entry point in the chamber.



For my first calc reactor, I was looking at minimizing price point. I would say I managed pretty well, considderinig total expence is under $20. However, I dont recomend this for anybody do to its structural weakness. I was just kinda a sucker for makeing it see-through so I could observe the CO2 pocket finding its equalibrium between the rate it adds CO2 vs the rate is disolves. Now I realize makeing it see through is pointless, and its not exciting to watch, and it really doesnt need to be watched, its pretty idiot proof and doesnt need a baby sitter.


Anyways, I will have to finish this post tomarrow. Its 4:16am allready now, and I only slept a few hours last night, so I gotta crash, Im getting delerious.

To be continued...

 

[Elmo18]

Anyways, I will have to finish this post tomarrow. Its 4:16am allready now, and I only slept a few hours last night, so I gotta crash, Im getting delerious.

To be continued...

It's good to know i'm not the only one awake at this hour....LOL..

- Ilham

 

[liveforphysics]

Ok, time to finish this post.

Here are some pics. I like the design and theroy of operation, I just dont dig how cheesey I made it. I used an old kitty litter container for the pump holding area, and these clear plastic tubese made to protect florecent lamp bulbs that cost 2.99 at home depot for an 8ft section. It uses a few pvc nipples and plumbing bends, and about 3 tubes of superglue. It uses homedepot white marble chips landscapeing rock ($3.99) for reactor media.
The sloppy duct tape and pvc crap you see was something i added as an after thought purely for a little structural reinforcement. That clear tubeing is so weak I was a little paranoid about it falling over and kinking/breaking.

Once again, I do not recomend this ghetto of a method. This was just intended to be a prototype for testing, but it worked so well and doesnt seem to leak anywhere that I havent found any reason to stop useing it.

I found it was really tough to get some pics of the unit since its mounted in the corner behind my tank. Here is an over head.

Here is a shot of the final buffer stage tube before the mixture enters the tank.

Ok, so It just became clear I need to draw a little diagram in MS paint so things can become more clear.

 

[liveforphysics]

Ok, here is a little diagram to make things more obvious as to what you are looking at in the pics.

The real beauty comes from the second upright tube filled with media. It gives the solution an area where it can raise the pH before it enters the tank. The way I set my drip up, it enters the tank at 520ppm Ca and a pH of 7.1. I dont have to worry a bit about the Ca reactor effect the pH of my tank. My tank has been holding around 440ppm-460ppm consistantly.

 

[liveforphysics]

Now, here is the one I made for a differnt one of my tanks more recently.

It doesnt function any better than the ultra ghetto one, but it would easily withstand a beating unlike the ultra ghetto one.

Method of operation is exactly the same.

This one is made from ABS and PVC fittings glued together with superglue. Its also filled with white marble chips from home depot.

 

[liveforphysics]

So, now things come down to tuneing. Do to the use of the buffer/neutralizing tube, this reactor is really easy to tune.

You can completely control the rate the CO2 is produced by changeing the amount of yeast. Less yeast, slower CO2 rate, which means it can last longer. Assumeing you dumped pleanty of sugar in (like 1-1.5cups), it will quit makeing CO2 when the amount of alcohol in the bottle raises to a lethal level for the yeast.

So, if you wanted to just have 1 bottle, you could just add more yeast. This would just mean you woudl have to change it more often (which really is no big deal). If you wanted to run around 6 bottles, with just an 1/8teaspoon of yeast in each one for example, you might have your CO2 supply last for 2-3 months. If you wanted to use wine makeing yeast rather than bread yeast, you could easily double the duration the bottles produced CO2 due to the increased tolerence for alcohol. I havent had to change any yet, but I know it would only take me about 5mins or so.

When you make bread for example, the yeast is in an enviroment with pleanty of oxygen. This enables it to have a exponential rate of growth good for makeing bread rise, but it would be terrible for our application. Fortunately, when yeast is kept anerobic, like in this application, it only metabolizes sugar and releases CO2 without growing.

This means you can easily tailor your CO2 rates, and they will stay constant right up the point the alcohol level rises too high and it dies.

So, basicially, just send in some CO2 at whatever reasonable rate. Then measure the Ca level in the drip. If the Ca level isnt high, slow the rate the water comes in by closeing off that valve on the entry a little more so the pH in the circulation area can drop low enough to disolve the marble chips.

If you want a Mg reactor as well, add in some dolomite rocks.


If you have questions, feel free to ask.

 

[Skimmy]

cool beans! do you have any better pics of the unit? they seem obscured by other equipment.
do you use a needle valve for your co2?

 

[plack]

So here I go with a few questions - and by the way is that ceramic beads next to the chateo in the super getto model sump?
Ok now on the sugar yeast bottles that make co2 can you tell me is it filled with soda water 1/2 way first then 1-1/2 cups of sugar then adjust with yeast is that about right? Then if any co2 amount were to escape from a bad fit on the soda lid to the outlet air tube I assume this would be such a small amount that it would not hurt anyone ? On the airline tubing valve what keeps the co2 from going up it into the tank? Or would that so small an amount it would not matter? Thanks for reading this and for this post
Paul

 

[ZooFreak]

Ilham,

Are you awake at that hour becuase you are a morning person or because you stayed up all night like Luke?

 

[liveforphysics]

Skimmer whisperer- No needle valve for CO2 flow control. The rate I set the yeast to metabolize the sugar = the CO2 flow rate. I set that rate through the amount of yeast. I mention it above. If I were to use some type of needle valve or something of that nature, it would not work at all. Useing a resistance means to limit the flow of a fixed production rate creates a self ballenceing pressure differential. So, if you restricted the flow through a change in CSA (cross sectional area in the valve), the pressure on the other side would build until the velocity through the restricted CSA point matched the original flow rate. The yeast operates the same under high pressure, so you dont need to worry about the amount of head pressure from the water level of the tank pushing against the line. If you wanted to use a real pressure vessel rather than a 2L bottle, you could mount a pressure regulator ini front of a needle valve which would then give you the same method of control you see with the status quo CO2 tank, but I really dont see the need for it. Perticularly since the second low velocity riser tube in the design makes things so simple to ballence.

Plack- Yep, those are ceramic beads that came with my fluval years back. They make an exellent 'pod pile' for the macro fauna to live in the fuge. The pods enjoy it a lot since there caretaker has a bad habbit of making so many frags that he runs out of rubble in the fuge for them to live in...

Plack- The only things that go in the bottles are warm tap water(doesnt have to be warm, but it starts the process a few hours sooner), yeast (the amount depends on the rate you wish to produce CO2), and sugar. No soda water involved.

A CO2 leak of this rate would be no more dangerous to your health than opening a few cans of soda or beer next to your tank.

The rate the CO2 disolves into the water is much too quickly to be possible for it to go up the airline. Perticularly since it enters right below the little 'lip' where the pipe pokes in past flush. A few CO2 bubbles should always be sitting there as the current of the water below them is rapidly disolveing them.

 

[wave98]

I think I have a fairly good understanding from your diagram. How often might you need to add the marble chips, and how do you get to their cavity to fill ?

> Barry

 

[liveforphysics]

The marble chips are very dense, and store a ton of calcium and carbonate for the volume they occupy. My first unit has settled perhaps 3/8" to 1/2" on a 20" tube, I would assume if this rate holds, it would take about 2-3 years before I would need more.


However, from the last speach with Bob Fernier i was at, he said to use dead coral skeletons in your calcium reactor becuase it provides ALL the elements in the proper ratios needed for coral growth. So, it would seem that packing it with large chunks of dead coral would be more ideal than marble chips. I will be useing this medium in the future.

To fill the device, I made the top and bottom have threaded pipe caps, so its simple to just turn the unit upside down, pack it with the medium, apply some ptethlon tape to the threads of the pipe cap, thread it on, turn it right side up, fill it with water, thread the top cap on, push the siphon tube with the little flow control valve into the top of the device and start it going.

Im excited that you are going to make one. I'm sure you will be VERY pleased with the superior design of the buffer chamber setup which enables the effulent drip to have a neutral pH, unlike other designs that can cause dangerous drops in your pH.

Good Luck!

Post pics and give a review when you finish, I'm sure it will help others bennifit.

-Luke

 

[wave98]

Luke, could you estimate the volume of media in your reactor, and your tank size ? Is there a reason for the suggestion for "large" chunks of skeleton vs say, small to medium rubble ( 1/8 to 3/8" ) ?

Also, could you give a bit more detail on your "pump chamber" consrtuction and installation.

Thanks ! > Barry

 

[LakeEd]

Luke,

VERY nice, and original DYI project!!!

On your PVC model version... what are you using for the larger section that would hold the powerhead? What are you using for fittings around both the powerhead power cord, and the airline tubing from your CO2 coke bottles?

When mixing the Yeast & sugar... is there some "Starting" dose you would recommend??? I see where you mentioned "If you wanted to run around 6 bottles, with just an 1/8teaspoon of yeast in each one for example, you might have your CO2 supply last for 2-3 months."... but re-read as I would, I don't see your suggestion for the starting amount of Yeast to use along with the 1-1 1/2 cups of sugar.

 

[liveforphysics]

For the power cord, I drilled 2 holes side by side that were just a tiny bit smaller than the x-section of the cord. Then I snipped off the end of the cord, pulled it through the small hole, positioned it how i wanted it, and super glued it. This is the same cord sealing method that things like powerheads use.

For the CO2 line input fitting, I used these slick little o-ringed push couplers with 1/8" NPT on the other side. I used these because I couldnt find just normal nipples that size for sale at home depot. I would appear that the push couplers are replaceing nipples for this small size tubeing. To mount it, I just drilled a hole about the same size, slathered it with super glue and threaded it in. I used the same method and part for the incomming water flow hose attachment.

With the yeast to sugar ratio, I dont have any quantified results for what quanity of yeast produces x bubbles/min. Temp varies it, as well as the type of yeast. If you want to have them run for very long term, get some wine makers yeast. I have no idea if it metabolizes faster or slower, but it will tolerate 2-3 times the alcohol level that the bread yeast I use is able to.

You have a 180gal tank, if its filled with high calcium demand creatures, I would look for perhaps 4-6 bottles each with 1/2 teaspoon yeast. Remember to mix it with really hot water and shake. Mixing with cold water seems to take about 2-3 days to start the process, where hot water only takes about 3-5hrs.

I havent found the ideal sugar amount yet, so I've simply been doing enough that I wont run out before the alcohol kills the yeast. I supose limiting reactants could be calculated fairly easy if you knew the exact alochol tolerance the yeast you were useing had, but just doing the sloppy guess method has been working so well for me, its difficult to justify the extra calculation.

If you want a bubble counter, just fill a 2L bottle 3/4 with water, drill 2 holes in the cap, have your input tube be long enough to nearly touch the bottom, and have the outlet be just pokeing into the cap enough to seal well.

Remember, with this reactor, if you just get a decent supply of CO2 comming in, you can regulate things to be exact with your control over the incomming water. The secondary buffer tube also makes worrying about it dropping your tanks pH mute. I personally havent seen another Ca reactor which is as safe as this one, nor one that even hits within 1/10th the price.

 

[aquarookie]

Hey Luke,

Thanks for the informative posts!

You inspired me to want to make a calcium reactor, as well as some aragacrete (or however you spell it) live rock. Where do you get the raw material for the live rock, by the way?

I had a question, though. You say you used ABS and PVC to build the reactor. As far as I know, they are both unsafe to use with warm water (at least when we talk about drinking water). I may be wrong, but wouldn't they leach toxic chemicals into the water and eventually hurt your reef?

When we wanted to replace our potable water lines with plastic, they said to use CPVC for the warm/hot water, PVC only for cold and ABS for sewer only. Would you agree/clarify this for me?

And hey, do you want to take a trip to Home Depot with me? I want to build one of these reactors

Thanks

Julia.

 

[MarineTeng]

everywhere for live rock, if you want to come to my house before the meeting you can see mine in my pond

 

[liveforphysics]

Sure Julia, I'm always willing to help a fellow DIY'er. I bought my portland cement at homedepot for 1.99$ (approximate guess) for an 80lbs bag. I recently learned that another type of cement that costs about 3 times as much is white, which makes your rocks look prettier before they get covered in coraline. I then bought 25lbs of oyster shell from this place called "Dels farm supply". It was something like 0.20$ per lbs if my memory serves me right. I make all my rock in this little cardboard box filled with crushed argonite, so all the rocks are covered in argonite when they have cured. I think it makes them look better with all the little shells and stuff stuck to them, but its not really important if you are on a budget.

I live in north seattle area and generally frequent the homedepot on auora and 95th (only an approximate guess of the cross street). I just ended classes for this term, so tomarrow whenever would work out fine for me (assuming I dont get called into work).

Good luck
-Luke

 

[MadTownMax]

excellent idea - love the low-cost CO2 generation most of all! Just wondering if you have any worries about trace amounts of alcohol, or any other impurities generated by the yeast (any molds?) These were the two points that prevented me from trying this method of CO2 generation.

There are hobbiest units for CO2 generation available at fish stores for those with planted tanks (some I believe use the same method - yeast) but I was told that they would not work for this - apparenly that was an oversight by them - probably clouded by a few $$$$-signs (between buying a $40 unit for planted tanks, or a $200 unit for reef tanks)

Thanks for doing this - it could make the hobby affordable for a whole new part of the population!

 

[liveforphysics]

You're very welcome. Im sure that some alcohol vapor enters the reactor. Fortunately, alcohol is actualy something that a lot of people dose into the tank as bacteria food (generally vodka is dosed). I havent put any thought into mold, but I supose it would be possible, assumeing it can tolerate the alcohol and and things, but I really doubt it could ever become an issue. I have never seen any growing in any of the bottles, but if I did, I would make sure to toss that bottle out and mix up a new one, so I dont think its the sort of thing that could really sneak up on you.

Maybe on Julias build we can actually do a step by step guide with ever piece of PVC and what legnths to cut things to and whatnot. That might help people out more who arent as experienced in the DIY game.