Glosso Factory CO2 Drop Checker Kit with Indicator Solution for Planted Aquariums (V2 Single Kit with 4.2dKH Solution)

Works great so far and claim that you don't have to keep changing Co2 indicator solution. Looks nice and used Co2 indicator fluid without adding additional blue. A little hard to pick up the green color when in range, however last tester never got to green-ever. I knew it had to be wrong, and it was. It takes most of the day to go from blue to green during 8 hours run time. Very impressed so far. Nice glass object with suction cup. No problems sticking to glass so far. Have it towards bottom of tank, not top 4 inches as they suggested.

Great instructions and they even provide a darkening solution that can help with the reading in different lighting and backgrounds. Excellent product!

Initially I put in too much darkening agent so it was hard to tell if it was blue or green, but once I dumped it and used just the base solution it became easy to read. Took around an hour to register from blue to green. Running around 3.3 BPS in a decently planted 55 gallon tank.Very simple to use and set into the tank. Great product.

Works as directed, came in good condition and works. I started off too high in the aquarium at first and wasn't getting proper readings, make sure you have it at least 4" below the surface. Blue means low Co2, Green is ideal, and Yellow is high Co2, the high readings sometimes looks like the ideal reading but after you watch it fluctuate over a few weeks you get used to reading it.

Works great. Easy to setup. Accurate.If you use this to gauge a safe co2 level for your fish, they will be dead before this will give you an accurate reading as it's not a instant read of your co2 levels in your tank. You have to watch your fish as you get it to the optimal green.

its nice to get a rough estimation on co2 levels, checking PH can be a pita but this works great. might try the darkening solution but so far not needed. When it gets a bit of algae on it, just pull the suction cup off (might want to leave that in warm water to soften) and then soak the glass in a bleach solution for a bit, rinse off and refill.

Attached the suction cup to the drop checker. Filled the glass ball up 3/4 of the way with the included 4.2 DKH solution. Added two drops of the darkening solution. Then stuck the whole thing in the tank about four inches below the water line. Gave it some time work after an hour or so the top of the solution was a little green. I turned up the CO2 just a little and came back a while later and the solution has been green since. No complaints. Next month when I refill the drop checker I might try one drop of the darkening solution and see how that looks.

The suction cup that came with the item kept detaching from the gñass every few days, so I had to refill the drop checker with fluid, every time only to see it detached again a few days later. I had to buy a replacement suction cup that did the trick, however the liquid in the drop checker becomes very light in color making the readings extremely hard. In other words, the glass piece is ok, but everything else is crap. I will have to buy testing solution from another manufacturer