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Our Verdict (Best For)
The Crystal Quest Thunder provided filtered water that tasted and smelled great. And although the countertop RO was easy to attach to our kitchen faucet and it was easy to switch between unfiltered and filtered water, we found several setup and usability headaches. For one, the system is incredibly slow. But more importantly, lab performance was disappointing with 5 (6) contaminants showing little to no reduction. We also observed drastic increases in copper (800%) and zinc (78,450%), either from priming issues due to the poor instructions or simple leaching. The copper increase was still within health standards, but zinc actually surpassed the EPA aesthetic guideline. Another con: The Crystal Quest Thunder has no NSF certifications or testing for contaminant reduction. Bottom line: Do not buy.
The Crystal Quest Countertop Thunder is a countertop reverse osmosis system that doesn’t require a plumbing connection (instead it connects to the kitchen faucet). It’s designed for use as a drinking water filter and can purify both tap water and properly disinfected well water (pre-treatment may be required).
As usual, we’ve tested the system with our own hands:
- Hands-on experience: We installed/assembled, used, and maintained it.
- Filtration effectiveness: We sent an unfiltered and a filtered tap water sample to a professional lab for analysis in order to determine real-life contaminant reduction capabilities. Plus, we checked for NSF certifications and other test data.
- More testing: We performed a taste & odor test, a filtration speed test, and a wastewater test.
- All other product aspects: We considered initial + long-term cost, product warranties, additional features, frequent customer complaints, etc.
Contents
Final Rating: /5.00
Filtration: /5.00
Usability: /5.00
Costs: /5.00
| Type: | Countertop Reverse Osmosis System |
| Price (Jan 20, 2025, No Short-Term Sales): | $202.23 (Use Code BOS5OFF for 5% Off!) |
| Yearly Cost for 500 gal Based on Rated/Claimed Filter Life (Aug 28, 2024): | ~$65-100 (Save 5% With Filter Subscription) |
(Use Code BOS5OFF for 5% Off!)
Final Rating: /5.00
What We Like Most
- Filtered water tasted and smelled perfect.
- Easy to attach to faucet and switch between filtered and unfiltered water.
What We Don’t Like
- No or partial reduction for 5-6 contaminants in our lab testing, with drastic increases in zinc (above aesthetic guideline) and copper (below health guideline).
- No NSF certifications and no 3rd-party testing for contaminant reduction.
- Poor instructions potentially resulting in filter priming issues.
- Only compatible with standard kitchen faucets, and tubes interfere with sink use.
- Extremely slow filtration and no storage tank.
- Produces way more wastewater than other countertop ROs.
- No filter life indicator.
- 3rd-party customers complained about leaking and lackluster instructions.
How the Crystal Quest Countertop Thunder Compares to…
25 Other Countertop Water Filters
In this video, Sara highlights our countertop water filter top picks. The Crystal Quest Countertop Thunder was included in our testing, but didn’t make the cut.
Please note: Our full guide on the best countertop water filters is available here.
Video Chapters + Comparison Sheet
- Link to Comparison Sheet
- 00:00 – Intro
- 00:33 – Our 26 Countertop Filters
- 03:14 – How We Tested & Rated
- 09:11 – Best Overall (AquaTru Classic)
- 14:33 – Best RO Budget Pick (AquaTru Carafe)
- 16:50 – Honorable Mention (Bluevua RO100ROPOT)
- 18:27 – Best “Regular” Filters (Aquasana CWM & ZeroWater)
- 27:47 – Best “Regular” Budget Pick (Waterdrop ED04)
- 33:04 – Summary
9 Other Countertop Reverse Osmosis Systems
In this video, Sara highlights our countertop RO top picks. The Crystal Quest Countertop Thunder was included in our testing, but didn’t make the cut.
Please note: Our full guide on the best countertop RO systems is available here.
Video Chapters + Comparison Sheet
- Link to Comparison Sheet
- 00:00 – Intro
- 00:27 – Our 10 Countertop ROs
- 01:15 – How We Tested & Rated
- 04:23 – System Setup & Filter Priming
- 04:38 – Sampling Process
- 05:41 – Lab Testing Disclaimer
- 06:07 – Taste & Odor Test
- 06:28 – Speed Test
- 07:05 – Pure-to-Drain Ratio Test
- 07:31 – Best Overall (AquaTru Classic)
- 10:49 – Best Budget Pick (AquaTru Carafe)
- 12:30 – Best for Hot Water (NU Aqua & APEC)
- 15:30 – Honorable Mention (Bluevua)
- 16:00 – Summary
Full Analysis of the Crystal Quest Countertop Thunder
Please note: Test results may be affected by a potential filter priming issue due to poor setup instructions.
Filtration: /5.00
1. Lab Results: /5.00
Remember that our before vs after lab comparison is not an exact science. It’s informational and subject to variability, inaccuracies, and interferences caused by natural fluctuations in water quality, accidental contamination, human error, instrumentation issues, and more. Furthermore, our lab-testing is limited to those contaminants present in our water supplies and at their respective concentrations. As such, it can only give us a general idea for how effective a certain water treatment product might be.
Lab Results Chart
| Potentially Harmful | Aesthetic Issues | Feed Water Level | Filtered Water Level | Reduction Rate | |
| Water Disinfectants | |||||
| Chlorine (mg/L) | ✖ | ✖ | 0.44 | 0 | 100% |
| Disinfection Byproducts | |||||
| Bromodichloromethane (µg/l) | ✖ | 2.68 | 0 | 100% | |
| Bromoform (µg/l) | ✖ | 4.42 | 0 | 100% | |
| Dibromochloromethane (µg/l) | ✖ | 5.32 | 0 | 100% | |
| Chloroform (µg/l) | ✖ | 1.36 | 0 | 100% | |
| Metals | |||||
| Copper (mg/L) | ✖ | ✖ | 0.01 | 0.09 | 800% Increase |
| Iron (mg/L) | ✖ | 0.01 | 0.01 | 0% | |
| Aluminum (mg/L) | ✖ | ✖ | 0.01 | 0.01 | 0% |
| Barium (mg/L) | ✖ | 0.05 | 0 | 100% | |
| Boron (mg/L) | ✖ | 0.1 | 0.04 | 60% | |
| Zinc (mg/L) | ✖ | 0.02 | 15.71 | 78,450% Increase | |
| Lithium (mg/L) | ✖ | 0.01 | 0.02 | 100% Increase | |
| Strontium (mg/L) | ✖ | 0.53 | 0.04 | 92% | |
| Salts | |||||
| Fluoride (mg/L) (Flawed?) | ✖ | 0.42 | 0.47 | 12% Increase | |
| RO Salt Rejection | |||||
| TDS (mg/L) | ✖ | 395.2 | 917.4 | 132% Increase | |
| Impurities NOT Detected in Unfiltered Tap Water Sample | |||||
| Manganese (mg/L) | ✖ | ✖ | 0 | 0.03 | |
| Explanation: | |||||
| Full Removal | |||||
| Considerable Reduction | |||||
| Concentration More Than Double of Unfiltered Water Sample | |||||
| Potential Leaching Reached or Exceeded the Strictest Public Health Guideline We Could Find | |||||
*100% means reduction to below the minimum detection level. To learn more about our testing procedures check our editorial guidelines.
Link to Filtered Water Report
Link to Unfiltered Water Report
Usability: /5.00
Costs: /5.00
Please note: This page is still a work in progress. Additional content and details will be added shortly – stay tuned!
About the Author(s)
Sara has been a lifelong home-improvement fan (she’s been hooked on This Old House since she was five) and taught herself any project she didn’t already know by watching YouTube tutorials. She is also an award-winning filmmaker. Armed with this skillset, Sara installs, primes, samples, uses, and maintains nearly every point-of-use water treatment systems we test – then brings her results to life on camera for our YouTube channel.
Raoul has a background in mechanical engineering and has been writing about home water treatment since 2015. He designs our product review processes, analyzes the results, and ties everything together. As editor-in-chief, he tries hard to keep the whole operation running smoothly behind the scenes.