The cheapest commercial product I could find was the Red Sea drop checker for $13 online, the nicer glass ones start at $25. That is ok if you need one only - well, MTS has it that I am in the need of a few more ... :) - so spending a lot of money became unfeasible.
Aunt google helps a lot if you are looking for ideas. There are quite a few nice ideas outside that inspired me. The following two just being a good example:
http://www.plantedtank.net/forums/diy/49546-simple-diy-drop-checker-under-2-a.html (http://www.plantedtank.net/forums/diy/49546-simple-diy-drop-checker-under-2-a.html)
http://www.aquahobby.com/board/viewtopic.php?t=50152 (http://www.aquahobby.com/board/viewtopic.php?t=50152)
With these ideas in mind I went to my favorite DIY store: DOLLARAMA. And they had exactly what I was looking for: A Tic Tac Toe shoot glas set - they make the perfect base for a nice looking drop checker. Five of the nine are clear glass, makes 5 drop checkers for a buck! :D I also picked up a pack of pencils for some plastic tubing.
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F3112%2Fdropchecker01cj8.jpg&hash=444b1bc2f1280098b0cd503967fb23c5c44343da)
Back home - this are the items I am planning to use. It turns out that a plastic wine cork has just a perfect tight fit inside these glasses - at this time just a hope. I didn't go cheap on the sucktion cups, I suggest to use Fluval or Eheim. The ones from the hardware store just wont last long under water - tried that. That's like $3 for 4 cups - the most expensive part of the drop checker if you dont count the wine :)
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F1770%2Fdropchecker02lm8.jpg&hash=bfb09c9630c94aae2672258157b8fc9033d0fc8d)
Tinker time: slice the cork, you want a plug for the glas; not to thin so you can still unplug it and not too big, that would be distracting- one should be good for three checkers. Cut the tube, drill a hole a bit to tight into the plug, fit the tube in, plug it on the glas - DONE! There is your drop checker.
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F5677%2Fdropchecker03pn7.jpg&hash=3ff12ee708856e4a828e4ef9bee9c6c0f1389d19)
Attach a suction cup and the drop checker is ready to use. I prefer tie wraps over glue - it has proven itself as more reliable and faster to make.
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F6966%2Fdropchecker04sm6.jpg&hash=c39d9821e352bcd616f1f1858252640fe45986d0)
Remove the plug to fill it with the 4dKH solution and pH indicater (methylen-blue) - 1ml should be enough, I used 2ml with 5 drops pH indicator. Plug back on, flip it around and set it up in your tank.
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F3848%2Fdropchecker05qi9.jpg&hash=90b2d4ef9a8963fc183ea92c6d604310670a2daf)
Find the drop checker ...
(https://www.ovas.ca/forum/proxy.php?request=http%3A%2F%2Fimg101.imageshack.us%2Fimg101%2F3652%2Fdropchecker06qp6.jpg&hash=2907b8159c7741806c79876d92f2bb94bcfb24a1)
I made 4 of those in an hour incl. setup. Each of them will cost you probably less than $1 - but this depends very much on your choice of wine ;D
Happy tinkering!
Thanks for sharing fishckopp.
Very nice have to consider this project much cheaper than the Red Sea ones for sure. thanks...
Well done, Robert! I wish you were there with your great DIY idea earlier, just before I spent $30 on two drop checkers..
Very cool....nice job!
Thanks guys :)
Now you know where to safe $$$ for your next tank(s) ... ::) ;D