Cobalt Neo-Therm 400W Submersible Heater fit check
Cobalt Neo-Therm 400W Submersible Heater is a 400W thin-profile heater. ReefCrafter's 2.5-5 watts-per-gallon band puts it at roughly 80-160 gallons of display water, before room temperature and redundancy choices. At this wattage a controller or a split two-heater setup limits the damage of a stuck-on failure.
Cobalt Neo-Therm 400W Submersible Heater: fits roughly 75-150 gallon systems. Specs, compatibility math, sizing risks, and alternatives before you buy.
Who it is for
Good fit for
- ✓ 75-150 gallon systems, per the catalog fit range.
- ✓ Roughly 80-160 gallons of display water at 2.5-5 W per gallon.
Not a fit for
- ✕ Tanks under about 75 gallons; it is sized above them.
- ✕ Systems over about 150 gallons without adding capacity elsewhere.
- ✕ Running alone on a large tank without a controller; split heat or add a controller.
Listed features
- submersible
- thin profile
- shatterproof
Compatibility math
Safe wattage band
Example: 400W is usually a planning fit for roughly 80-160 gallons before room-temperature and redundancy choices.
ReefCrafter checks both the low-wattage failure and the oversized stuck-on failure.
Risk notes
- A single oversized heater can cook livestock faster than a beginner notices the problem.
- High wattage should be split or controller-protected on most reef systems.
Professional fit context
- Check wattage, controller, redundancy, tank size, and whether two smaller heaters are safer.
- Cobalt Neo-Therm 400W Submersible Heater fits roughly 75-150 gallon systems; confirm that range against the final display volume, sump volume, and livestock plan.
Alternatives to compare
- Innovative Marine Helio PTC Smart Heater 350W
350 W vs 400: less heat for smaller tanks.
- Aqueon Pro 300 Adjustable Submersible Heater 300W
300 W vs 400: less heat for smaller tanks.
- Bulk Reef Supply BRS 300W Titanium Aquarium Heater System WiFi
300 W vs 400: less heat for smaller tanks.
Full spec snapshot
- Category
- Heaters
- Build tier
- Balanced
- Estimated price
- $120
- Tank fit range
- fits roughly 75-150 gallon systems
- Format
- Thin Profile Heater
- Heater wattage
- 400 W
Related reading
Questions
What size tank is a 400W heater like the Cobalt Neo-Therm 400W Submersible Heater for?
ReefCrafter's 2.5-5 W per gallon band puts 400W at about 80-160 gallons. Cold rooms push toward the smaller end; tanks over 50 gallons are safer with two smaller heaters.
What tank size is the Cobalt Neo-Therm 400W Submersible Heater for?
ReefCrafter's catalog fit range for it is 75-150 gallon systems. Confirm that against your final display volume, sump volume, and livestock plan rather than the box label alone.
What should I compare the Cobalt Neo-Therm 400W Submersible Heater against?
Innovative Marine Helio PTC Smart Heater 350W (350 W vs 400: less heat for smaller tanks); Aqueon Pro 300 Adjustable Submersible Heater 300W (300 W vs 400: less heat for smaller tanks); Bulk Reef Supply BRS 300W Titanium Aquarium Heater System WiFi (300 W vs 400: less heat for smaller tanks).
