Vertex RX4 Calcium Reactor

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This item has been discontinued.

Vertex Aquaristik

Vertex RX4 Calcium Reactor

Vertex RX Series Calcium Reactors
Stable parameters are the key to a successful Reefscape. Calcium, being utilized by a myriad variety of oceanic life forms, including corals and crustaceans, is amongst the most important of these parameters. As the fifth most abundant ion found in natural saltwater, it is absolutely critical that Calcium is kept as a constant. One of the greatest apparatuses we have at our disposal to maintain this parameter is the Calcium Reactor. By dissolving Aragonite-based mediums down to their basic elements, Calcium Reactors allow for a continuous influx of calcium into the system. Vertex™ RX-Series Calcium Reactors now bring this potent tool home to you with all the features and qualities you need at values you can easily afford.

Efficient and Easy to Use
Designed for maximum capability, Vertex™ RX-Series Calcium Reactors feature an advanced recirculating chamber design, allowing for extremely proficient use of media and CO2.

A large bubble counter makes for easy visibility and effortless adjustments. Fine tuning of flow/effluent is also straightforward with the high quality Vertex™ Needle Valve included with each reactor.

Vertex™ RX-Series Calcium Reactors utilize the exclusive Gas Stable Use (GSU) concept to aggressively dissolve CO2, recycle unused CO2, and extract only reduced CO2 effluent. As a result, Vertex™ RX-Series Calcium Reactors are more efficient than other available designs.

Robust Construction
Vertex™ RX-Series Calcium Reactors are made to last; being assembled only with high-grade cast acrylic and heavy-duty PVC parts. All Vertex™ products are rigorously tested for safety, efficiency and reliability.

Exclusive Features

  • Advanced reverse-flow design
  • All John Guest fittings
  • Precision Vertex™ Needle Valve
  • Large bubble counter
  • Onboard pH probe port
  • Quick-Lock lids
  • CO2 dissolution chamber prior to main reaction chamber
  • Excess CO2 recycling system
  • Output CO2 reduction module
  • Phosphate reduction chamber
  • Easily disassembled for maintenance

  • Footprint 11" x 9½"
  • Height 22"
  • Pump 21W
  • Primary Media Chamber 14” x 4” Diameter
  • Phosphate Media Chamber 7” x 3” Diameter
  • Rated up to 180 gal

Product Manuals & Documentation

Vertex RX4 Calcium Reactor

Owner's Manual available for download in Adobe PDF file format

Manufacturer Info

Vertex Aquaristik Aquarium Supplies
Vertex Aquaristik is a German company with many fresh ideas and innovations new to the aquarium hobby. Their products are developed only after extensive research and testing in simulation and field trials. They purposely abuse products during the test phase to determine if they can handle the wear and tear of aquarium keeping. The company is determined to provide solutions that stand the test of time. No expense is spared during the production process to ensure customers enjoy uncompromising quality and value. Vertex Aquaristik manufactures high-quality calcium reactors, protein skimmers, zeolith-based filters, wavemakers and accessories.



Experience Level: Expert

Good product

I have an RX6 Duo on my 155 gallon reef aquarium. It is the best calcium reactor I have had. I have been on this hobby for more than 10 years and I had my share of calcium reactors. Very well built. Strong components. The only improvement I did to the unit was installing a T connector with a valve to the tubing that goes from the center of the main reactor chamber to the pump. As you open the valve to the outside, the system will purge any air that is inside the camber by itself. This trick helps in the initial set up of the system as there is some air trapped in the media as you fill up the unit with water. I wish it came also with the pump to let water into the system instead of having the inlet feed by gravity. That is my next project with this system.

1 out of 1 found this review helpful

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Experience Level: Beginner


This was for my first saltwater tank. I had purchased the Reef Octopus & that was a waste of money. Nothing worked. I read up on this one and purchased. When I received it I couldn't believe how easy it was to setup and get going. Some reviews said it leaked at first but I found that not to be true. If you merely do as the instructions indicate and use plumbing tape or silicone on the connections you won't have any problems but that's with any equipment like this. I also couldn't believe how easy it was to setup for someone new at this as I am. You won't believe how well made it is either. I would have expected to pay much more.

5 out of 6 found this review helpful

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Experience Level: Intermediate

Big bang for your buck

This reactor is constructed like many that cost over twice as much and performs even better. It is easy to put together and even easier to maintain. You might consider purchasing some magnesium granules to add to the reactor media then you can keep your magnesium and calcium levels up at the same time. The Tom Aquatics Aqua Lifter Dosing Pump works perfectly with this reactor and I strongly suggest purchasing both at the same time. If you do, don't forget the Tom Aquatics Aqua Lifter Suction Pre-Filter which keeps the junk out of the pump. Also, the directions don't tell you this, but be careful NOT to fill the reactor chamber too full. There is a connection between the reactor chamber and the CO2 chamber that houses the pump. If you fill the reactor chamber too full, media will flow into the chamber with the pump and two things can happen. One, it blocks the tube that joins the two chambers and second it can hurt the pump. When you first turn the unit on, the reactor media rises up a few inches so beware! I suggest only filling to the lower half of the decal they put on the chamber. It is easy to add more media later. And speaking of media, the CaribSea A.R.M. Aragonite Reactor Media works great in this unit. I strongly suggest you consider it. A very nice feature of this reactor is the ability to put a pH probe right in the reactor chamber. This lets you fine tune things quite nicely. This is a feature often found only on much more costly units So as I said this unit is a big bang for the buck. I strongly recommend it!

9 out of 10 found this review helpful

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Experience Level: Intermediate

Incredible value

Have had this set up for about a month now. First of all, the quality of materials and construction is excellent. It came with no assembly instructions, but fortunately there are some good pictures on the net so it wasn't difficult to figure out. Initially the pump made a ton of noise, but a phone call was all it took to get it quickly replaced and now it's fine. The included needle valve makes fine adjustment of the effluent very easy. The extra chamber for GFO is nice to have since I have little real estate inside my stand.

16 out of 16 found this review helpful

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Experience Level: Intermediate

You Would Not Believe!

I have not set this up yet, but I have to let you all know what I think of it. This is by far the best thing I have seen since sliced bread. The unit is so well made that it is the best on the market. I had another custom unit that I ordered and I was so unhappy with and it was more than $300.00 more than this unit. This Vertex RX4 is a very quality piece of equipment that I am just blown away. I just do not see how this company can produce a product this well at this price. On top all that, Marine Depot sent it to me with no sales tax and free shipping. Thanks Marine Depot, Your my only source for everything I own for my 400 Gallon Reef!

23 out of 33 found this review helpful

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