Seachem does not currently manufacture its own dosing pump product. When people search for a "Seachem dosing pump," they're typically looking for a pump to automatically dose Seachem's line of aquarium additives, including Seachem Reef Fusion, Seachem Reef Builder, Seachem Reef Complete, and Seachem Stability. Any quality peristaltic dosing pump works with Seachem additives, and this guide explains how to choose and set up the right pump for the Seachem products you're using.

I'll cover which Seachem products benefit from automated dosing, which pumps work best with them, how to calculate your daily dose requirements, and how to avoid the common setup mistakes that cause parameter swings instead of stability.

Which Seachem Products Work With a Dosing Pump

Seachem makes a wide range of liquid additives, but not all of them are good candidates for automated dosing. Some need to be dosed daily in small amounts (ideal for a pump), while others are best added manually during water changes.

Seachem Reef Fusion 1 and 2

Seachem Reef Fusion is a two-part calcium and alkalinity supplement system, similar in concept to BRS two-part but formulated with a different ionic balance. Reef Fusion 1 is the alkalinity component (sodium bicarbonate and sodium carbonate) and Reef Fusion 2 is the calcium component (calcium chloride).

These are the primary candidates for automated dosing because they need to be added in small amounts throughout the day to maintain stable parameters. Dosing them once daily in a single large amount causes parameter spikes; spreading the dose into 12 or 24 increments per day keeps alkalinity and calcium stable within 0.1 to 0.2 dKH and 5 to 10 ppm respectively.

Seachem Reef Builder

Reef Builder (sodium bicarbonate) raises alkalinity without affecting calcium. It's used for alkalinity correction in tanks where calcium is already adequate. Dosing with a pump works for routine small adjustments, though single-session corrections are typically done manually.

Seachem Reef Complete

Reef Complete (calcium chloride) raises calcium without affecting alkalinity. Same situation as Reef Builder: useful for targeted correction, and pump dosing works for routine maintenance.

Seachem Stability

Stability is a bacterial product for cycling tanks and supporting biological filtration. It's not a good dosing pump candidate because it's typically used in larger amounts during tank setup or after medicating, not in small daily maintenance doses.

Compatible Dosing Pumps for Seachem Additives

Since Seachem doesn't make a pump, here are the options reef keepers use with Seachem additives:

BRS Single Dosing Pump

The BRS (Bulk Reef Supply) single-head peristaltic dosing pump is the most common entry-level choice, running $40 to $50. It delivers approximately 1 mL per minute on average (actual rate varies by tubing wear and should be calibrated at setup). It's programmable for dose frequency and can be controlled via a simple wall timer or connected to an aquarium controller.

For Seachem Reef Fusion dosing in a 50 to 100 gallon tank, a single BRS head handles one part. You need two heads (one for Reef Fusion 1, one for Reef Fusion 2) for a complete two-part setup.

Neptune Systems DOS

The Neptune DOS is a two-head peristaltic pump that integrates natively with the Apex aquarium controller system. It includes optical flow sensors that verify actual fluid delivery and alert you if a line becomes empty or kinked. This is the most reliable option for reefers already running an Apex controller.

For Seachem Reef Fusion dosing, the DOS manages both parts with individual programming and flow verification. The flow sensor feature means you know immediately if dosing stops, rather than discovering a week later that your alkalinity has been dropping unchecked. Current retail is around $200 for the DOS unit alone.

Kamoer FX-STP2 and FX-STP4

Kamoer makes reliable peristaltic dosing pumps in 2-head and 4-head configurations at competitive prices. The FX-STP2 handles two-part dosing and connects via WiFi for app-based programming. The FX-STP4 adds two additional heads for magnesium, probiotic dosing, or other additives. Both are well-reviewed alternatives to BRS and Neptune in the $120 to $200 range.

Jebao DP-4 and DP-M4

Jebao's dosing pumps are the budget option in the category, with 4-head configurations running $60 to $80. They work for Seachem additive dosing but have a shorter lifespan than BRS, Neptune, or Kamoer equipment and require more frequent tubing replacement. Acceptable starting point if budget is tight, but expect to upgrade within 2 to 3 years.

For comparisons of these pumps across a wider range of applications, our best dosing pump for reef tank guide covers the full field.

Calculating Your Daily Seachem Reef Fusion Dose

Setting up your dosing pump correctly starts with knowing how much Reef Fusion your tank actually consumes each day. Guessing leads to parameter instability; calculating from your actual consumption leads to stability.

The process:

  1. Stop all supplementation and test your alkalinity (dKH) and calcium (ppm) at the same time over two consecutive days. This gives you your daily consumption rate.

  2. Calculate using Seachem's dosing guidelines: Seachem Reef Fusion 1 raises alkalinity by approximately 2.67 dKH per 1 mL added to 100 gallons of tank water (similar to BRS two-part). Reef Fusion 2 raises calcium by approximately 4 ppm per 1 mL per 100 gallons.

  3. Example: A 100-gallon tank consuming 0.5 dKH per day needs 0.5 / 2.67 × 1 mL = 0.19 mL of Reef Fusion 1 per 100 gallons per day. For your actual tank volume, adjust proportionally.

  4. Verify with actual Seachem dosing directions. Seachem lists specific volumes on each bottle. Cross-check your calculation against their label instructions.

  5. Spread the dose into small increments. Program the pump to deliver 1/24th of the daily dose every hour, or 1/12th every two hours. Consistent small doses are better than fewer large doses.

Setting Up Your Pump for Seachem Additives

Once you have your dose calculated, the setup process:

Step 1: Calibrate the pump. Run it for exactly 60 seconds and measure the output with a graduated syringe or small measuring container. Compare to the pump's claimed rate. Adjust the programmed rate to match the actual delivery. Tubing wear causes this to drift over time, so recalibrate every 3 to 6 months.

Step 2: Route dosing lines into the sump. The return pump chamber of your sump, with active water movement, is the best injection point. Never dose directly into the display tank or onto coral surfaces.

Step 3: Separate Part 1 and Part 2 outlet points. Keep the two dosing lines at least 6 inches apart. Reef Fusion 1 (alkalinity) and Reef Fusion 2 (calcium) react when they contact each other in concentrated form, creating calcium carbonate precipitate that clogs lines and wastes additive.

Step 4: Test after 5 to 7 days. Your alkalinity and calcium should be stable at or near your target. If they're still dropping, increase the dose by 10% and wait another week. If rising above target, reduce by 10%.

Step 5: Test weekly thereafter. Parameters drift as coral growth changes. A frag pack that arrives and starts growing fast will increase consumption faster than the pump is currently delivering. Quarterly recalculation keeps you ahead of the curve.

Our best aquarium dosing pump guide has detailed breakdowns of each pump's programming interface, which matters when you're setting up 24-increment dosing schedules.

Common Mistakes When Dosing Seachem Products With a Pump

Using expired or old Seachem products: Seachem additives have shelf lives. Older products can have reduced efficacy, meaning you're dosing the calculated volume but not getting the expected parameter change. Check the manufacture date and replace if more than 2 years old.

Not testing before you start dosing: If you don't know your baseline alkalinity and calcium, you can't calculate the right dose or know whether the dosing is working. Test first; dose second.

Dosing into the display tank near corals: Concentrated Reef Fusion 2 (calcium chloride) can cause localized tissue damage to corals near the dosing outlet. Always dose into the sump or a high-flow area away from livestock.

Running both parts through the same tubing: If you share a tube between Part 1 and Part 2 (say, by switching which container is connected), the residual in the line will react with the opposite part next time. Use dedicated tubing for each part.

Not accounting for evaporation-driven top-off: Auto top-off systems replenish freshwater evaporation, which concentrates additives in the tank until the top-off water dilutes them. If you have a significant evaporation rate and irregular top-off, your effective parameter levels fluctuate independently of your dosing. A reliable auto top-off system (like the Tunze Osmolator or Innovative Marine Ghost Skimmer AIO models with integrated top-off) stabilizes this variable.

FAQ

Is Seachem Reef Fusion better than BRS two-part? They accomplish the same goal through very similar chemistry. BRS two-part is considerably less expensive per dose, especially for larger tanks. Seachem Reef Fusion uses a slightly different ionic balance with magnesium included in the formulation, which some reefers prefer for its "completeness." Both work well. Cost per dose over 6 months usually favors BRS two-part significantly.

Can I use a dosing pump for Seachem Prime? Prime (sodium thiosulfate, sodium hydroxide, and chelated compounds) is a water conditioner, not a maintenance additive. It's used in relatively large amounts for dechlorination and isn't appropriate for continuous automated dosing in an established tank. Dose Prime manually as needed.

How long does a bottle of Seachem Reef Fusion last for a typical reef tank? For a 50-gallon mixed reef tank consuming 0.3 dKH of alkalinity per day, a 500 mL bottle of Reef Fusion 1 lasts roughly 90 to 120 days. Larger tanks and SPS-dominant systems with fast-growing corals consume additives considerably faster.

Do I need a dosing pump or can I just dose manually once a day? Manual dosing works, but once-daily dosing creates a parameter spike followed by a slow drop until the next dose. Twice-daily manual dosing is significantly better. An automated pump with 12 or 24 increments per day is better still, and for SPS corals that are sensitive to alkalinity swings, the pump is worth the investment.

Summary

For automating Seachem additive delivery, a quality peristaltic dosing pump like the Neptune DOS, BRS Single Dosing Pump, or Kamoer FX-STP2 is what you need. Calculate your actual daily consumption from real parameter testing, calibrate the pump before relying on it, spread doses into frequent increments, and test weekly to stay ahead of changes in coral growth and consumption. That workflow turns what would otherwise be daily manual effort into a weekly test-and-verify routine.