AA Aquarium Green Killing Machine Internal UV System, 9-watt

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$64.99 (-19%) Chewy Price
$79.99 List Price
Promo, New Customers Only: Spend $49+, Get $20 eGift Card + Free Shipping with code: WELCOME
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FREE 1-3 day delivery
Free 365-day returns

Pay in 4 interest-free payments of $16.25. .

About This Item

Details

  • Promotes dazzling, clear water in your finned friends’ abode.
  • Designed to be easy to install—no tools necessary!
  • Helps remove murkiness from aquarium water.
  • Helps create a green-water-free home for your fish!
  • Comes with a powerhead.

Instructions

Learn More About AA Aquarium From Our Team of Experts

Frequently bought together

Questions & Answers

46 Customer Questions

how can you tell if the light is actually on? you cant see it at all , it is sealed up. Pump has flow, but want to be sure its on

Answer by kittenpapa • Jul 18, 2020
When your water goes from much to crystal clear. This thing is a miracle and took my new 75 gallon tank from heartbreak to crystal clear in a few days.

My water is crystal clear now If I have no timer how often should I turn on machine

Answer by Chewy • Nov 11, 2020
UVC bulbs typically last about 6-9 months in constant use. Some bulbs can last up to a year. To lengthen the service of your bulb, we suggest once your water is sparkling clear for 7 full days, start using your UV on a limited as needed basis. Run it with your light timer or only on weekends, etc.

Does it kill parasites like Ich?

Answer by Chewy • Nov 09, 2020
This sterilizer does not kill parasites.

After I do a partial change, I add good bacteria. How long should I keep the sterilizer turned off?

Answer by Chewy • Feb 23, 2021
There are times that you do not want to operate your Green Killing Machine 24/7. We would recommend turning the GKM off for 1 week to allow the added good bacteria to grow on the bio filters. After that, use the GKM as needed to maintain desired water clarity.
Reviews
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4.3
Rated 4.3 out of 5 stars
433 Ratings
Terms & Conditions

345 Customer Reviews

Rated 5 out of 5 stars
By Stephanie on Jan 6, 2026

The amazing quickness that it cleared our tank!

Our tank was green, I mean middle of an algae bloom major, and we couldn’t get the algae to quit no matter what we did. Wrapped the tank to keep light out, turned

Our tank was green, I mean middle of an algae bloom major, and we couldn’t get the algae to quit no matter what we did. Wrapped the tank to keep light out, turned light off and even adjusted the feedings. This machine seriously helped and was VERY MUCH worth the purchase!

Rated 1 out of 5 stars
By Kevin on Jan 16, 2026

Why cant Chewy deliver at the Front Door

Second delivery in a row where the package wasnt left at the front door. Can you please speak with you delivery company to get this right...Totally unacceptable

Second delivery in a row where the package wasnt left at the front door. Can you please speak with you delivery company to get this right...Totally unacceptable. Instructions say Front Door not Mail Box which is far away.

Rated 5 out of 5 stars
By Steven on Jan 25, 2026

Worked really well.

Long standing problem with this tank, the water was so murky you couldn't through to the back side. After one week with the UV system, the water is clear again

Long standing problem with this tank, the water was so murky you couldn't through to the back side. After one week with the UV system, the water is clear again.

Rated 5 out of 5 stars
By JAMES on Dec 22, 2025

Green killing machines work

Green killing machines work great I have the 24watt and this 3 watt both are really good and price is great compared to other UV products. Only downside on this

Green killing machines work great I have the 24watt and this 3 watt both are really good and price is great compared to other UV products. Only downside on this brand the pump head could be a little bit noisy compared to a higher quality one but it's not that bad.

Rated 5 out of 5 stars
By Gregory on Dec 20, 2025

Really Works!

So I’m definitely a septic when it comes to possible gimmicks like I thought the GKM would be. But I was pleasantly surprised! My water went from green to crystal

So I’m definitely a septic when it comes to possible gimmicks like I thought the GKM would be. But I was pleasantly surprised! My water went from green to crystal by 7 days!

Rated 1 out of 5 stars
By Olivia on Jan 25, 2026

Not working?

Not sure if I have a faulty one or not but its been running for 2 weeks in my 10 gal tank and its not made a bit of difference.

Not sure if I have a faulty one or not but its been running for 2 weeks in my 10 gal tank and its not made a bit of difference.

Rated 5 out of 5 stars
By David on Oct 28, 2025

I am totally amazed

I ordered the UV filter Sunday afternoon. It arrived at my door the following day Monday afternoon. Install the UV filter and Tuesday morning by aquarium 75% better

I ordered the UV filter Sunday afternoon. It arrived at my door the following day Monday afternoon. Install the UV filter and Tuesday morning by aquarium 75% better looking. I am totally amazed. Thank you for the great product and the fantastic shipping time. I recommend this product to anyone that has a problem.

Rated 5 out of 5 stars
By Rachel on Dec 16, 2025

Works great!

Omgosh. We tried everything for weeks to get rid of the algae bloom in our tank and nothing worked. Purchased this for our 40 gallon tank and it worked right aw

Omgosh. We tried everything for weeks to get rid of the algae bloom in our tank and nothing worked. Purchased this for our 40 gallon tank and it worked right away!

Rated 5 out of 5 stars
By Rodney on Jan 22, 2026

This product works great

This product removed all the alagea from my fish tank, water is clear.

This product removed all the alagea from my fish tank, water is clear.

Rated 5 out of 5 stars
By Rose on Sep 10, 2025

Worked When Nothing Else Did

Tried everything to clear a bacterial bloom. Left the tank alone, did water changes, checked parameters (all great), fed less. Was getting frustrated and decided

Tried everything to clear a bacterial bloom. Left the tank alone, did water changes, checked parameters (all great), fed less. Was getting frustrated and decided to get a 3w for my 29 gallon. Took two weeks but now it's crystal clear. Happy to finally enjoy my tank again