Free calculators and tools for saltwater reef hobbyists. No account required.
Compare cherry and other Neocaridina colors, Crystal Red and bee, tiger, Amano, ghost, bamboo and vampire shrimp by size, feeding, care level and water parameters, and print a comparison sheet.
Find cute, funny and clever fish names by type, color and personality, save favorites and download a meet-my-fish card.
Compare Yellow, Kole, Hippo, Powder Blue, Naso and other reef tangs by adult size, tank length, reef safety, ich risk and aggression, and check which tang fits your tank.
Compare bubble tip, carpet, long tentacle and other reef tank anemones by clownfish host, light, tank size and sting risk, spot pest Aiptasia and Majano, and pick the right anemone.
See how heat and light stress bleach coral in an interactive simulator, then find out why your reef tank coral is turning white with a guided checklist and printable log.
Work out how many gallons or liters your pond holds for any shape, then size the pond liner, pump GPH, waterfall flow and pond salt dose.
Check if your reef tank can keep a mandarin dragonet fed, compare pod supply vs demand, run a night pod count and get a copepod seeding and culture plan.
Identify bristle worms, fireworms, Aiptasia, flatworms, pods and other hitchhikers from live rock or frags, see if each is friend or pest, and get a removal plan.
Compare 40+ saltwater gobies by tank size, reef safety and sand habit, pair shrimp gobies with the right Alpheus pistol shrimp, and check if a goby fits your tank.
Identify clownfish species and designer morphs by colour, bars, and pattern, compare Ocellaris vs Percula, and find the best clownfish for your tank size.
Plan marine ich treatment in a hospital tank with hyposalinity water-swap amounts, copper and tank transfer calendars, and the display tank's 76-day fallow date.
Work out how long to drip acclimate fish, shrimp, snails, starfish, or corals, the drip rate in drops per second, and volume milestones, with a built-in timer.
Build a dated cleaning and replacement calendar for floss, socks, sponges, carbon, GFO, and biomedia, staggered to protect beneficial bacteria.
Calculate freshwater aquarium salt treatment amounts in grams, teaspoons, and tablespoons, with staged doses and redosing after water changes.
Estimate a practical freshwater or saltwater quarantine tank size from fish count and adult length, with a setup checklist and quarantine timeline.
Calculate the moon phase, illumination, lunar age, and upcoming new and full moon dates with reef observation guidance.
Calculate parts per million from solute and solution amounts, then convert PPM to PPB, percent, and mg/L for aquarium water testing.
Solve C1V1 = C2V2 for stock or final concentration and volume, then get a practical stock-plus-diluent recipe with unit conversions.
Calculate your tank's water volume for rectangular, bow front, cylinder, hexagonal, L-shape, and corner pentagon shapes. Accounts for rock, sand, and equipment displacement.
Check if your water parameters are in the ideal range for reef, FOWLR, or freshwater tanks. Get actionable recommendations when levels are off.
Calculate exact dosing amounts for calcium, alkalinity, and magnesium supplements. Supports BRS, ESV, Brightwell, and generic products.
Calculate how much salt mix you need for water changes. Supports Red Sea, Instant Ocean, Fritz, Tropic Marin, and more.
Estimate reef tank startup and monthly costs for equipment, livestock, supplies, and electricity by tank size.
Estimate monthly and annual reef tank power consumption from lights, heater, pumps, skimmer, and chiller wattage at your kWh rate.
Pick the right protein skimmer rating for your reef tank based on water volume, bioload, and stocking style. Includes recommended skimmer type.
Calculate ideal flow rate (GPH turnover) for your reef tank from volume and coral type. Get powerhead count, per-powerhead GPH, and placement guidance.
Build a reef LED schedule with ramp-up, peak, ramp-down, PAR targets, channel suggestions, moonlight timing, and coral acclimation guidance.
Calculate the right heater wattage for your reef or freshwater aquarium from tank volume, ambient temp, and target temp. Includes dual-heater redundancy advice.
Calculate how many pounds or bags of sand, gravel, aragonite, crushed coral, or planted substrate you need from tank dimensions and bed depth.
Estimate glass or acrylic panel thickness from tank dimensions, water height, bracing style, and planning safety factor for DIY aquarium planning.
Create a dated cycling chart for ammonia, nitrite, nitrate, water changes, and fishless or fish-in cycle milestones.
Check compatibility between 36 common reef fish species. See aggression level, reef-safe status, tank-size minimums, and pair-specific warnings.
Estimate safe aquarium stocking based on tank volume, filtration, and 36 common saltwater fish species. Includes compatibility and minimum tank warnings.
Identify and treat 12 common reef tank algae - GHA, bryopsis, cyano, dinos, and more. Visual guide with causes and treatment steps.
Identify 30+ reef aquarium corals - LPS, SPS, soft corals, and anemones. Filter by type, difficulty, and lighting; see care needs at a glance.
The Printable Reef Logbook gives you water testing, dosing, maintenance, and livestock worksheets you can print or save as a PDF.
These tools give you a snapshot. My Reef Log gives you the full picture - log water tests, track trends, manage livestock, and stay on top of maintenance.
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