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baker.shawn

DIY kalk reactor

Rating: 7 votes, 4.57 average.
7 Comments
by
baker.shawn
, 03-01-2011 at 12:58 PM (3873 Views)
As many of us know Kalkwasser is one of the easiest and most affordable ways to add calcium and alkalinity to a reef tank as well as maintain pH in smaller heavily stocked aquariums and lightly stocked larger aquariums. about 6 months ago I decided to make my own reactor here are some pictures of the build process, if anyone has questions please leave a comment and I’ll get back to you

--Materials
(1) Acrylic tube 4”OD- 2’
(3) ¼” acrylic 6”x6”
Various scrap acrylic
(8) Nylon wing nuts and screws
(1) Pc fan
Weld-on 16
(2) Rare earth magnets
(1) Stir bar 1 ½”
(1) Old cell phone charger
(2) ¼” john guest fittings
silicone
**forgive me if I forgot anything

To keep my lime water saturated i decided to use a DIY magnetic stirplate what i found on a homebrewing website. I did this mostly because I did not want to have to mess around with pluming, unseals and maxi jets being clogged and or corroded

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I really wish I would have taken pictures of the rest of the construction of the body but it was my first time doing acrylic welding so I wasn’t really thinking of taking pictures. The base and lid of my reactor are both square for simplicity. I build two legs on my base to make room for where the modified pc fan would sit. Attaching the body to the base was straight forward. I can’t stress how important it is to have clean SQUARE cuts, I ran in to problems here which will be in my conclusion

Creating the “neck” portion where the lid attaches was a challenge because I didn’t have a big enough drill bit. I used a ¼” bit and my drill press to make about 40 holes in the perimeter of the 3½” hole I needed I then used the friction of the bit to melt the acrylic between the holes giving me a very rough 3½” hole afterwards I cleaned everything up with a drum sander it turned out great

To prevent leaks I used a thick bead of silicone (now replaced with a o-ring) sealed by the 8 nylon wing nuts and bolts, the process was easy and just a matter of lining up the holes. I did not have a tap to put a thread on the acrylic where my john guest fittings attached so I drilled a rough hole then heated up a bold with the same thread after working it in I let it cool before removing it, creating a pretty good thread ( I still used a bit of silicone around the fitting)
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During the 6 months of use I found a couple problems with my design

1) I’m not very good at making water tight acrylic welds, the fact that the tube wasnt cut square by the plastic shop didnt help
2) The stir bar keeps the kalk so well suspended it had to be put on a timer 5min every 6 hours
3) During the 6 hours the lime water and the fresh top off water coming in separate, to solve this I added a tube to the water coming in to the reactor to take it nearly to the bottom
4) The stir bar is beginning to wear away the acrylic, to solve this in my second proto type I plan on using a glass insert in the bottom

Over all I’m very happy with the turnout, once I perfect the stir plate portion I plan incasing it in a projectbox and adding a potentiometer to control speed, i will also consider having a plastic shop build the reactor for me so that i can have the joints and welds done by a pro

once again if you have anyquestions just leave a comment i check the forums like 383847462626377 times a day so ill be sure to get back to you.
-shawn

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Updated 03-01-2011 at 01:10 PM by baker.shawn

Categories
‎ DIY projects

Comments

  1. DJ in WV's Avatar
    what if you used a rod or pvc pipe for your stir plate drilled the centerof it and used a nylon screw to fix it to the bottom and reverse the poles of the magnet so it pushed the stir rod up instead of pulling it to the bottom that would fix the acrylic wearing and shift it to the screw that would be easy to relace if worn. you could also attach some flat stock at a angle to make it as like a prop. if that fan is dc a pot would be the way to go for speed control. Alsp found a pretty good site that had a diy on keyhole flanges ill try to find it again if your interested
  2. baker.shawn's Avatar
    hey DJ I’m not 100% sure what you mean with your suggestion to hinder the wearing however I have a pretty good idea of what your saying the used fan does not produce much torque so I’m very limited on what I can do, with the addition of kalk it makes start up at times tough at first so I’m worried if there was any more mass( such as props) it would not spin freely. The reason behind choosing a lab grade stir bar is because it is made to withstand extreme pH conditions and not deteriorate long termthe fan is DC I’m currently using 3.5v I tried 12v and 6v but the initial speed was so much that the magnetic bond between the stir plate and the stir bar was broken and the stir bar would just shake around all over the place while the fan turned crazy fast. because I’m already using such a low voltage it limits my controllability big time if I have it turned down to low there simply isn’t enough torque and it won’t spin too much voltage and I run in to the problems I mentioned about earlier
  3. Midnight's Avatar
    you could also decrease the distance between the fan and the bottom of the reactor.
  4. baker.shawn's Avatar
    midnight- i ended up doing that not to long ago actually with really good results, the magnets mounted to the fan are now 1/4" away from the reactor it has definitly lowered the frequency of null starts when i add to much kalk and it settles in a mass during a 6 hour off period. im considering steping up to 6v now and seeing it it will work this time. can anyone suggest a useable resistance for a pot to control speed? i went to the electronics store yesterday and they looked at me like an idiot when i told them what i was doing...they werent very helpful with picking out the right pot and i ended up buying one that had basicly no effect on the speed of the fan i think it was 1000k ill have to go find the package
  5. melev's Avatar
    That came out pretty good. Thanks for sharing it with us. I wouldn't have thought of a computer fan for the magnet stirrer.

    A large holesaw would have made that one piece easier to cut/bore out. Our a router bit, tracing the inner surface of the 4.5" tubing with its bearing.
  6. Neelixx's Avatar
    I would definitely go much higher than 1000k I would probably get a pot that maxes out at maybe 100M or more. I dont think the current is very high, but, even so, you may get a small bit of heat from it.
  7. baker.shawn's Avatar
    melev- thanks! for my first shot at it i agree it didnt come out too horrible, i dont have a router but im considering buying one for my next reactor build. when i came across the plans for the magnet stirrer i was actually looking for instructions on home distilling, then i got thinking of using it for water changes to mix salt water for hours then i thought of mixing kalk

    neelixx- thanks for the help! ill have a look around the surplus electronic stores and see what i can find if it helps at all the transformer im now using is 6v @ 1A the fan is rated for 12v @ .25A