Aquavitro is a product line by Seachem focused on reef chemistry, and while the Aquavitro brand is well-regarded for supplements like Calcification (a two-part calcium solution) and Reef Fuel, Aquavitro does not manufacture a standalone calcium reactor. If you're searching for a calcium reactor to pair with Aquavitro's reef supplements or to replace them, you're looking at third-party reactors from brands like Korallin, GHL, Reef Octopus, or Two Little Fishies, while potentially continuing to use Aquavitro chemistry products alongside.
Calcium reactors are one of the most effective long-term calcium and alkalinity dosing methods for reef tanks, particularly medium-to-large systems. Understanding how they work, which brands make reliable units, and whether they make sense for your system size will help you decide whether a reactor or the Aquavitro two-part supplement approach is better for your situation.
What Aquavitro Makes for Reef Chemistry
Seachem's Aquavitro line is specifically positioned for high-demand reef tanks. Their most relevant products for calcium and alkalinity management:
Calcification: Aquavitro's calcium supplement. A 150 mL bottle dosed daily raises and maintains calcium in a mixed reef. The formulation is concentrated and designed to work alongside their Eight.four alkalinity product. Runs $18-25 for 150 mL, $45-60 for 350 mL.
Eight.four: The alkalinity/carbonate hardness supplement in the Aquavitro line. Used in conjunction with Calcification to maintain the 2:1 ratio of calcium to alkalinity dosing most reef keepers target.
Fuel: An organic carbon and energy supplement for coral that feeds heterotrophic bacteria and provides carbon for coral tissue synthesis. Not directly related to calcium/alkalinity dosing.
Synthesis: A comprehensive reef supplement covering minor and trace elements.
These products follow the two-part dosing methodology: you dose a calcium component and an alkalinity component separately in balanced quantities. This works well for most reef systems and is significantly simpler to set up than a calcium reactor.
What a Calcium Reactor Does and Why Hobbyists Use Them
A calcium reactor dissolves calcium carbonate media (usually coral skeleton or aragonite reactor media) using CO2-acidified water, releasing calcium and alkalinity directly into the system water in naturally balanced ratios.
The advantage of a reactor over two-part dosing or Aquavitro supplements: at large calcium and alkalinity demands (heavy SPS-dominated tanks, large systems, tanks with high coral growth rates), a reactor provides calcium and alkalinity indefinitely from cheap calcium carbonate media rather than requiring regular liquid supplement purchases.
Cost comparison over time:
For a 30-gallon SPS tank consuming 80 ppm of calcium per week, Aquavitro Calcification and Eight.four at full dose would cost roughly $40-60 per month in supplements at heavy dosing rates. A calcium reactor running ARM aragonite media ($25 for 5 lbs, enough for 3-6 months) represents far lower consumable cost once the reactor itself is paid off.
The breakeven point varies by tank size and coral load, but most hobbyists find reactors pay for themselves in supplement savings within 12-24 months on medium-to-large systems.
Calcium Reactor Brands Worth Knowing
Korallin Calcium Reactor C-1502
The Korallin C-1502 is one of the most widely used and reviewed calcium reactors in the hobby. It's a German-made unit in the $180-250 range that handles tanks up to 250 gallons. The design is straightforward: a recirculation pump moves water through the media chamber, CO2 is injected into the chamber to create mild acid, and the effluent is dripped back into the sump.
The C-1502 has been in production in essentially the same form for over 15 years, which means there's extensive documentation on setup, adjustment, and troubleshooting from hobbyist forums.
GHL ProfiLux Calcium Reactor (Deltec Integration)
GHL partners with Deltec for calcium reactor integration into their ProfiLux controller ecosystem. Deltec reactors are expensive ($400-700+) but very well-engineered. If you're running a GHL ProfiLux controller for your reef, the integration with pH probes and automated CO2 regulation is seamless.
Two Little Fishies (TLF) Reactors
Two Little Fishies makes reactor media (ARM aragonite is the industry standard) and their own C.A.R.X reactor line. The C.A.R.X 250 handles tanks up to 500 gallons and runs $250-350. TLF ARM Coarse Aragonite Media ($25 for 5 lbs) is the most commonly recommended reactor media in the hobby.
Reef Octopus and Vertex
Reef Octopus and Vertex (an Aqua Medic brand) make well-reviewed calcium reactors in the $200-400 range. The Reef Octopus CR140 handles tanks up to 250 gallons and is well-regarded for ease of adjustment and low maintenance.
DIY Reactors
A functional calcium reactor can be built for $50-100 using a clear acrylic cylinder, a small recirculation pump, CO2 fittings, and standard plumbing components. Detailed DIY guides exist on Reef2Reef and Nano-Reef for hobbyists comfortable with the plumbing.
CO2 Requirements for a Calcium Reactor
Every calcium reactor requires a CO2 source, which means a CO2 cylinder and regulator. If you don't currently run CO2 in your system, add $80-150 for a 5 lb refillable CO2 cylinder ($30-50) and a dual-stage aquarium regulator ($60-100).
CO2 consumption: A calcium reactor on a medium-sized SPS tank uses roughly 1-2 lb of CO2 per month. A 5 lb cylinder lasts 2-5 months depending on tank demands and your CO2 bubble rate setting.
pH monitoring: CO2 injection acidifies the sump water if effluent pH drops too low. Most experienced reactor users monitor display tank pH and sump pH separately. Target effluent pH of 6.5-6.7 for most media. Running the reactor effluent through a second stage filled with ARM media helps raise effluent pH before it enters the sump.
When to Use Two-Part vs. A Calcium Reactor
Two-part dosing (Aquavitro Calcification + Eight.four or similar) makes more sense when: - Tank is under 75 gallons - Coral load is light to moderate - Simplicity is a priority - Budget for upfront equipment is limited - You prefer not to manage CO2 equipment
A calcium reactor makes more sense when: - Tank is 75+ gallons - SPS corals with high calcium and alkalinity demand - Monthly supplement costs exceed $50-80 - You already run CO2 for another reason (planted section, refugium) - You want to minimize recurring consumable costs
Kalkwasser (limewater) dosing is a middle-ground approach: calcium hydroxide powder dissolved in top-off water provides calcium, raises pH, and has some precipitation benefits. Aquavitro doesn't have a kalkwasser product specifically, but Seachem's Reef Kalk works in this application.
See Best Aquarium Equipment and Top Aquarium Equipment for current equipment recommendations across reef dosing systems.
Setting Up and Dialing In a Calcium Reactor
Initial setup takes a few hours. The main adjustment variables are:
- CO2 bubble rate: Start at 1-2 bubbles per second into the reactor chamber. Adjust based on effluent pH.
- Recirculation flow rate: Higher recirculation dissolves media more efficiently. Set per manufacturer recommendations, typically 100-200 GPH internal.
- Effluent drip rate: How fast the reactor output enters the sump. Start slow (30-50 mL per minute), test calcium and alkalinity after 48 hours, adjust until parameters stabilize.
- Media depth: Fill the reactor 75-80% full of media. Too little reduces efficiency; overfilling restricts water flow.
Expect to spend 2-4 weeks fine-tuning before parameters stabilize. Once dialed in, calcium reactors run with minimal attention beyond monthly media top-offs and CO2 cylinder refills.
FAQ
Does Aquavitro make their own calcium reactor?
No, Aquavitro (Seachem's reef-specific line) does not manufacture a calcium reactor. Their reef chemistry products like Calcification and Eight.four are liquid two-part supplements. If you're building a calcium reactor-based dosing system for a reef, you'll choose a reactor from brands like Korallin, Two Little Fishies, GHL/Deltec, or Reef Octopus and use TLF ARM aragonite as media. You can still use Aquavitro trace element supplements alongside a reactor-based calcium and alkalinity system.
Can I use Aquavitro products alongside a calcium reactor?
Yes. Many reef keepers use a calcium reactor as their primary calcium and alkalinity source while supplementing with Aquavitro Synthesis or Seachem Reef Trace for minor and trace elements that a calcium reactor doesn't supply. Two-part dosing for calcium and alkalinity isn't typically used alongside a reactor because the reactor handles those parameters.
What calcium reactor media should I use?
Two Little Fishies ARM (Aragonite Reactor Media) Coarse is the most widely recommended option in the hobby for its consistent dissolution rate and broad availability. Carib Sea Geo Marine Reactor Media is a comparable alternative. Some hobbyists use a mix of coarser and finer media for more consistent dissolution. Avoid generic aquarium gravel or non-aragonite substrates, which dissolve unpredictably.
What tank size makes a calcium reactor worth the investment?
Most reef keepers find the breakeven point at 75-100 gallons with a moderate-to-heavy SPS load, where monthly two-part dosing costs approach $40-60. For smaller tanks or lightly stocked mixed reefs, two-part dosing (including Aquavitro products) is simpler and often more cost-effective when the reactor's upfront cost and CO2 system are factored in.