That should be a very interesting DIY project. I personally prefer the colored water approach, but for those with color vision problems or a desire for more precise numbers this would be ideal. I'm assuming the grommets are a donut with a slit around the outside to grip the "sheet metal" they go thru, and an undersized hole in the middle to grip the probe? That would be much cheaper and simpler than the Heyco devices, so it sounds great. You can make 500 of these devices now and make a million bucks on ebay!

The Viewtainers have a good rubber seal that's good enough for the reactors, and they cheap, 1.99$ easily melted and formed with a lighter etc, a suspended cap is all that needs to be added.

They(Viewtainer) also make smaller ones so you can add one inside the other etc.

No need for a grommet, but if you wanted to make a nice heavy duty pH measurement checker out of Acrylic, which is a material I most often tend to think with, I would have a use for them thar grommets:-)

I might make a nice acrylic version for a client etc.
I'll also need to make them 5 liters of Reference solution also


Regards,
Tom Barr

Doh!

a simple U shape and a PCV or acrylic tubing bent in a U shape with a cap on one end.


IIIIII
III III
III III

The capped end would have the ref solution, the other open to the tank.

You'd just leave an air gap on the top of the U.
You do not need to see the solution other than to make sure it's there etc and add a pH probe to this.

They already make pH in line probe assemblies.

A 1" PCV elbow(the one's with the flat end, not curved) and a grommet would likely work well.

Regards,
Tom Barr

This and VaughnH's orginal thread are really good stuff fellas !

Makes sense. Thanks!

great stuff guys!

I placed a link to this thread at a dutch aquarium forum: Veni Vidi Vissie :: Begin.
everybody should know this!


greetz,

yme

A PVC tee and a PVC elbow, joined at the side outlet of the tee would also work, with a cap on the bottom outlet of the tee, and the probe entering the top outlet of the tee. The elbow would point down into the water to establish the air gap. About $1 worth of fittings. Getting the probe sealed where it enters the tee would be the only mildly hard part.

Now how would you modify the output on this to give us a Co2 meter?

DIY CO2 Controller - The Real Thing - The Planted Tank Forum

Since the KH is already given, we would just use this algorithm,

CO2 = 3 x [degrees KH set] x 10^(7-pH reading from controller)

The way I would modify that DIY controller is to nod my head knowingly, then do a google search for a cheap pH monitor. I know a bit about electronics, but not enough to tackle that. The way I have modified meters before is to add another scale to them that reads the correct values, but that only works with analog meters.

Have you had a chance to prototype this yet? This could be the ultimate CO2 checker. You need to keep the pH probe wet all of the time anyway, so this could act as storage device for the probe too - just remove it from the tank water and leave it in a small cup of other water. This will also cure acne, hives, and lumbago, and accurately forecast the weather! Really. (Maybe I need to reduce my meds?)