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Cal Aqua Labs Pearl CO2 Drop Checker

17 reviews Write a Review
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Cal Aqua Labs' PEARL is a dual-compartment CO2 checker that allows the user to accurately compare the CO2 level in your aquarium side-by-side against a standard reference. The unique space-saving design places the reference chamber right inside the the indicator chamber. The inner chamber holds the CO2 reference solution, whereas the outer chamber carries a CO2 indicator solution. The reference solution color corresponds to 30 ppm of CO2 - a level that is widely accepted for good plant growth in most aquariums.

No more guessing on the shades of green. No more looking back-and-forth at color sheets to compare. You know the precise CO2 level simply by comparing the colors in the two compartments side-by-side. Simply adjust your CO2 level so that the color of the indicator solution matches that of the reference solution. Don't guess, be sure! It's as simple as that.

The Pearl is hand-crafted using only the highest quality, laboratory-grade, borosilicate glass for maximum strength, durability, and visual clarity. Each piece is unique.

Unique dual-compartment design. Inner compartment holds the Reference solution, while the outer compartment holds the Indicator solution

No solution preparation needed. Required solutions are premade and included

Improved durability and ease of use

Easy to fill and remove solutions from both chambers

Simple to use, simple to read, higher accuracy than other single-compartment checkers

Approximate size without suction cup: 2"x2.3" (WxH)


One (1) Suction Cup

One (1) Bottle of CO2 "Indicator" Solution (15 mL)

One (1) Bottle of CO2 "Reference" Solution calibrated to 30ppm CO2 (15 mL)

2 Reference chamber plugs

Instructions for use

Customer Reviews

17 reviews

  • 3

    With flaws

    I find reviews helpful so always take the time to write them myself. This is cool, but given the cost, i would like to point out on the one i received has no less than 3 clear and obvious flaws. But how perfect do you expect? It goes inside an aquarium so who knows and I am admittedly new to glassware. But just stating fact, as I must have clearly gotten a newer glassworker. What bothers me is there is a larger than normal "Tab" on top of the inner bulb, so it sticks out pretty obviously and is not as pictured.

  • 5

    The best of the best in glassware is Cal Aqua Labs.

    I bit the bullet on a full Cal Aqua Labs set to back up my current GLA set. This drop checker is beautiful. Everything out of Cal Aqua labs is hand crafted excellence. Get them while supplies last as I hear Cal Aqua Labs in Thailand is closing shop!

  • 5

    Pictures do no justice, its glass aquarium art at its best.

    I own all sorts of glassware mostly ADA and china made stuff. This glassware is ultra premium. Much nicer than ADA or anything Ive seen. The glass is highly polished, its milky smooth and clarity like nothing Ive used. You can tell a craftsman created these with care. I love it.

  • 5

    Work of art drop checker.

    This is super nice, like very very nice glassware. I figured it was expensive for a reason and you can tell. A very complicated piece of glassware for sure, and it looks so darn cool.

  • 5

    It gets no better than Cal Aqua Labs.

    I was ripped to shreds to learn of Cal Aqua Labs closing I had to load up. In our tank room we have 4 aquaecapes going full time for the last 11 years. We have used so much glassware, ADA,VIV you name it. Nothing holds a candle to Cal Aqua Labs, VIV is the absolute worst glassware available. If your reading this, just a friendly warning. Cal Aqua Labs glassware is leaps and bounds in design and craftsmanship. You could place these works with glass art pieces. Dont confuse these works with anything else on the market, dont even try. Thank you GLA, I ordered two units and hopefully I will have these in the box until my others need replacing. I dont even plan to use these at all. I will be keeping these in the original box.

  • 5

    Everybody is right, Cal Aqua Labs is the absolute best in the hobby.

    I was debating this vs the cheaper ones but Im so glad I did. Opening this out of the box I knew right away it was premium quality. Pictures do not due justice. Its so nice I want to hang these on this years Christmas tree but my wife would destroy me.

  • 5

    The highest quality drop checker you will find.

    This is fact. Ive used so many cheap glass drop checkers and after all them breaking in some weird form or another I invested into GLA's Cal Aqua Labs drop checker. I did not know it was this high of quality. People, Cal Aqua labs makes artisan piece of aquarium glassware. This is not your mom and pop shop level of glassware. I own ADA and VIV glassware and Cal Aqua Labs make them look like cheap knock offs. Especially the VIV glassware which still cost me a lot. Comparing the two is ridiculous. VIV glassware is as if a child made it, warped and nothing is straight. The ADA blows VIV away, but the new version I have is nothing like the old version from 2007. I dont know why, but totally different now. If you can afford it go with Cal Aqua Labs, you will be impressed, I surely was.

  • 5

    co2 drop checker

    excellent product that adds class to tank.

  • 5

    Simple, easy to use

    Directions are straight forward. I appreciate the idiot proof nature of the inner bubble

  • 5

    Pinnacle of aquarium glassware.

    If your reading this review its because you landed on Green Leaf Aquariums drop checker page because its the best there is. This is no joke, you will absolutely not find higher quality well made designs anywhere. Craftsmanship is artisan, quality is clearly paramount at Cal Aqua Labs because nothing comes close to this level of quality. The knock off glassware is just absolute junk. You can tell when you see junk just by how crooked and lopsided everything is. Well, not with Cal Aqua Labs. I shit you not, its a premium price and your getting actual true artisan glass. Even my wife was impressed and she has no clue what she's even looking at. Thats all you need to know.

  • 5

    Co2 checker

    Beautiful/functioal, shipping communication was great, arrived on time!

  • 5

    Top of its class

    I have many drop checkers and Cal Aqua Labs drop checkers and glassware in general is the best. Make no mistake, this is the highest quality glassware available. From design to the flawless packaging.

  • 5


    Great product! We have to use a drop checker. Why not make it one that has the reference color built into the checker. A win, win situation.

  • 5

    Pearl Drop Checker

    Very easy to correctly set CO2 levels having the reference media inside chamber

  • 5

    Very Nicely Made

    A beautiful product, with simple instructions that allows for a quick install. This adds an easy way to my tank for checking CO2 levels. It’s been up and running for a day now, but it looks great. I do wish the instructions included information on how often you should refresh the solutions or if they never need to be changed.

  • 5

    No more guessing

    Simple to use and makes it easy to fine tune your CO2. Highly recommended!

  • 5

    Drop checker

    Love my new drop checker, having the reference fluid in the small bubble is a great addition!!!

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