DIY Kalkwasser Gravity Drip System

A lot of folks don't want to spend the money to set up auto top offs with switches pumps and all the associated stuff.  There are low tech ways to drip kalk into your system like the "glug jug" or just pushing a pin into a milk just full of kalk.  Niether of these systems was satisfactory for me because they weren't easily refillable and reliable about the feed rate of the fluid into the system.  I designed my own gravity drip system with the goals of being, cheap, reliable feed rate, easily refillable.  Here is the write up about it.

I wanted to be able to replace my evaporation with kalkwasser but don't have room below my tank for an elaborate system.  The only answer is a custom setup to make the best use of space!  I decided to make mine out of acrylic (my first acrylic project, and no it isn't hard to do) with a reliable drip system that is adjustable for speed.

Step 1:  I decided that I could build a custom spaced "tank" out of 3/8 acrylic that would hold about 2 1/2 gallons of kalkwasser.  This meant i would have to refill it about once a week or maybe twice to replace evaporation.  This fit in perfectly with my "goal" of having to do aquarium maintainence only twice a week.  So down to home depot I went and found that 3/8 acrylic is the thickest they have.  I bought a sheet about 20x30 for about $9 bucks.  so far so good.

Step 2:  I needed acrylic solvent to "weld" the acrylic together to form the tank.  Chris at Fish4U on highland just south of 39th had a little bottle with more solvent than I'll ever use for about $6.  Perfect, everything I needed to make the "tank" obtained for about $15!

Step 3:  I decided how big i wanted the older to be by measuring the available space "on" my sump under my tank.  This way it could sit on the edge of the tank maximizing space and still use gravity drip to drip into the sump slowly.  perfect for a kalk auto top off!

Step 4:  With measurements in hand i used my table saw (you could use a bandsaw, or a jigsaw if you are really steady with your hand) to cut the pieces to size.  mine is approx 12 inches long, 4 deep, and 8 inches tall.  I did a little experimenting and found that you don't want more than 1/16 variation in the piece sizes, meaning you need a reasonably straight cut, but if you do woodworking or something similar you are used to tolerances MUCH tighter than this, so do not worry.

Step 5:  Glue all the acrylic together using the "pin" method.  Look this up to see how it works, its not very hard to get a good bond, although i think it will take some practice to make the bonds "look" good and not get solvent in places that will cloud the acrylic.  This is a great first project to work with acrylic because you probably don't care about the end "look"

Step 6:  Drill a 1/4 inch hole in the end of the "tank" about 1/2 and inch above the bottom.  This allows the drip tube to draw from just above the bottom so that any precipitation from the kalk doesn't get sucked up and clog the tube.  After a month now I've decided to wash that junk out just to be safe.  Super simple.

Step 7:  Obtain an "iv drip" package from a medical supply or have a VERY nice WMAS member borrow one from their hospital job.  cut the tubing (3/16ths) into a 3 foot long section and feed it halfway through your hole.  gob that bad boy up with silicon on either side and make sure you get a very nice seal.  let it dry overnight.

Step 8:  cut the tubes to length and put the flow control regulator on it, put it on top of your sump, pour some kalk from your bigger kalk container (i use a 5 gallon water jug that i always shake up when i add RO and let settle before i pour the clear kalk into the gravity feed tank,  adjust your drip rate with the adjuster and you're set!

Tips:    have the "end" of the drip tube actually under the surface of your water the sump.  if you don't eventually the tip "crusts" over and you end up dripped slower and slower and eventually stopping.

i found that even with 2 1/2 gallons and a 12 inch longest dimension the 3/8 acrylic looks like its "bending" out.  its not anywhere near breaking but if i had to do it again, i would probably put a brace across the top because i'm anal like that.

i left the top open on mine so i could easily just pour into it from a 5 gallon jug without having to move anything.  to make it all a little more sanitary if i had to do it again i would make the top of it about 3/4 covered with just enough room for pouring in.  this would prevent sloshing around if i have to move it a little bit better.

a gravity feed system WILL feed slightly faster when the tank is full than when the tank is almost empty.  determine your drip rate when the tank is full so that you never add kalk too fast (bad) but then aren't adding quite fast enough by the time its empty.  eventually you'll find the happy medium that you never add too fast but don't add to slowly and you'll never have to top off manually again!

hope this helps other people out,  feel free to ask some questions i'd be more than willing to help out!

it made a huge difference for me since i don't have to add calcium/alk all the time now... i check it once a week now and its rarely out of wack and i adjust as needed.  definitely saving me on maintainence which is ideal!