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Home » Saltwater Aquarium Supplies  » Calcium Reactors  » Kalkwasser Reactors  »  Two Little Fishies KW Reactor 300 (Kalkwasser Reactor)
Two Little Fishies KW Reactor 300 (Kalkwasser Reactor)

Two Little Fishies KW Reactor 300 (Kalkwasser Reactor)

Average Rating 4 10
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Two Little Fishies KW Reactor 300 (Kalkwasser Reactor) Information

Product Manuals & Documentation

The KW Reactor™ 300 creates saturated kalkwasser solution every time the feed pump is switched on to replenish evaporated water. Gentle mixing is achieved with a rotating sprinklerhead that is “powered” by the pressurized water feed

Technical Data
  • Capacity: Use with up to a maximum of 1 cup calcium hydroxide.
  • Aquarium Size: One reactor for aquariums up to 300 gallons (1135 Liters).
  • Recommended Pump Size: ca. 200 - 300 gal/hr (760 - 1140 L/hr). The pipes automatically reduce the flow to a small stream.
  • Connection for Hoses: 1/2 inch (12.7 mm) i.d. The inlet and outlet flexible 90° fittings rotate to suit your installation.
  • Approximate size: height: 15.25", width: 5". reactor diamater: 4"

Manufacturer Info

Two Little Fishies
Two Little Fishies, Inc. was founded in 1991 to promote the reef aquarium hobby with its introductory video and books about reef aquariums. The company now publishes and distributes the most popular reef aquarium reference books and identification guides in English, German French and Italian, under the d.b.a. Ricordea Publishing.

Two Little Fishies KW Reactor 300 (Kalkwasser Reactor) Reviews

Average Rating
(10 reviews)
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Great for the price

Reviewers Rating Excellent!

Posted: 7/4/2012 from BURBANK, CA UNITED STATES
4.5 5
Experience Level: Beginner

Comments: It does exactly what it's supposed to - mix Kalkwasser with your top-off water and pour the limewater solution into your tank. Be warned however: maintenance is required otherwise this reactor will quickly render itself useless! The sprinkler head frequently gets chalked up by calcium carbonate and requires a vinegar dip to keep it spinning. As far as the pump is concerned, I would highly recommend something high up in their 200-300 GPH specification. Maybe a tad bit higher even. I'm using a Maxijet 1100 (297 GPH) and it barely generates enough pressure on the sprinkler head to mix the thick Kalk that settles around it. All things aside, it does it's job well enough. It's not as beefy, robust or maintenance free as the big boy reactors but hey, at 1/4th the price, there is no room to complain.

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Reviewers Rating Unsatisfactory

Posted: 3/10/2012 from BRONX, NY UNITED STATES
1.0 5
Experience Level: Intermediate

Comments: Check valve failed after one week of operation, making this reactor useless...

1 of 3 People found this review helpful, did you? Yes No

Love It

Reviewers Rating Excellent!

Posted: 10/15/2011 from GRAND JUNCTION, CO
5.0 5
Experience Level: Intermediate

Comments: Very solid product, and couldn't ask for a better price. I used it with my reefkeeper and it works great...

2 of 4 People found this review helpful, did you? Yes No

Ex Reactor Bargain

Reviewers Rating Excellent!

Posted: 9/21/2011 from ARROYO GRANDE, CA UNITED STATE
5.0 5
Experience Level: Intermediate

Comments: This is a great design. The dribble into the sump requires a timer with the auto top-off. If not the thing goes off a lot. Works perfect and see the difference right away in the tank. The best challange is to calculate as best possible dose to add into the reactor for the calcium. A++++

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Reviewers Rating Great

Posted: 6/19/2011 from GAINESVILLE, FL UNITED STATES
4.0 5
Experience Level: Intermediate

Comments: anouther great item from two little fish! works great easy to setup and takes up very little room a must have for any reef with an auto topoff

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almost perfect

Reviewers Rating Average

Posted: 4/3/2011 from SOUTH OZONE PARK, NY UNITED ST
3.0 5
Experience Level: Intermediate

Comments: ive had this for some time now. its built well and the concept in design works well. But the only problem with this device is the 1/2 barbed check valve is a really cheap part and is likely to fail. when it fails it allows the lime water inside the reactor to flow backwards into the fresh water resevoir. im currently looking for a better replacement whcih is a little more durable. 1/2 inch barbed check valves are not found locally for me

5 of 6 People found this review helpful, did you? Yes No

Best bang for your buck.

Reviewers Rating Excellent!

Posted: 2/2/2011 from MANASSAS PARK, VA UNITED STATE
5.0 5
Experience Level: Intermediate

Comments: I've had the TLF Kalk Reactor installed for two days now and everything is working great. The install was so easy. I have it working with my JBJ ATO and they seem to work very well together. Can't wait to see the SPS grow and keep my calc levels up! I wish I knew about this reactor sooner.

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Great for money.

Reviewers Rating Great

Posted: 1/27/2011
4.0 5
Experience Level: Intermediate

Comments: The reactor is very easy and flexible to set up. It works great for about 4-5 days, then the sprinkler stops spinning. However, it is very easy to clean and only takes about 2 minutes, if that (the sprinkler can be removed and cleaned while leaving the reactor full of limewater).

2 of 3 People found this review helpful, did you? Yes No


Reviewers Rating Excellent!

Posted: 1/12/2011 from FLOWERY BRANCH, GA UNITED STAT
5.0 5
Experience Level: Intermediate

Comments: I have this KW reactor 300 on a 500+ gallon marine shark breeding tank and it will easily take care of more than a 300 gallon system! It is completely silent, dependable, and it has a simple yet effective design. The price makes it a really good deal too and you can dose other things with it as well through your Automatic top-off which makes it very versatile.

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Works well

Reviewers Rating Great

Posted: 7/31/2010 from CROTON ON HUDSON, NY UNITED ST
4.0 5
Experience Level: Expert

Comments: While the others that use stirrers might be better, this is a much better price. I found using the "maximum of 1 cup calcium hydroxide" is too much, I add a couple of table spoons a week. Combined with a float switch on my Digital Aquatics RKE, this makes water top-off and kalk completely automatic.

17 of 17 People found this review helpful, did you? Yes No

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