01 / GOAL
Choose the reef you actually want.
Forgiving softies, bright LPS, mixed reef, SPS showpiece. Start with the outcome, not the spec sheet, and we'll size the build around what that reef needs.
Premium reef planning · free because we don't sell gear
Plan a reef tank that won't punish you later.
A free, vendor-agnostic planner for first-time and intermediate reefers. Pick your goal, tank, livestock, and gear. ReefCrafter checks compatibility, sizing, and upgrade risks before the cart, so the expensive part is the tank — not the lesson.
My 75 gal Mixed Reef
risk reviewTankRed Sea Reefer 250· 65 gal displaybaseline set
SkimmerReef Octopus Classic 110· rated 100gthin margin
Lighting2× Hydra 32HD· covers 60×24 footprintcoverage ok
FlowSicce Syncra 3.5 + 2× MP40· 38× turnovertarget hit
Avoided mistake · undersized skimmerCHECKED 2s AGO
Rules checked
23before you buy
Gear categories
9tank to RO/DI
Checkout
nonebuy where you want
Planning cost
$0free to use
Built by a reefer
Made by Max Rodes after watching too many first builds get wrecked by the wrong skimmer, light, or fish.
Vendor-agnostic
We don't sell gear and we don't take checkout. Buy wherever you want — the build decides, not the store.
Transparent rules
Every check shows the math behind it. The rule engine is open — no “AI says.”
Free, with disclosure
No paywall, no card. Vendor links may earn a commission and are clearly disclosed.
How it works
A premium planning studio, not another aquarium spreadsheet.
Reef tanks fail when the decisions stop talking to each other. ReefCrafter keeps the whole build in view: the goal, the glass, the animals, the gear, the budget, and the risks hiding between them.
02 / BUILD
Add the tank, livestock, and gear.
Pick a tank, sketch the fish list, then choose lights, flow, heat, filtration, and RO/DI. Every choice updates the requirements downstream.
03 / CHECK
Fix the weak spots before they cost you.
ReefCrafter flags the skimmer at the edge, the heater with no redundancy, the light that misses the footprint, and the fish that outgrows the tank.
The compatibility engine
It catches the stuff that ruins month four.
✓
Skimmer rated for 100 gal
DISPLAY 65G · BIOLOAD MED · OK ✓
!
Single heater on 75 gal tank
REDUNDANCY REQUIRED > 50G · WARN
✓
Total flow @ 38× turnover
MIXED REEF · TARGET 30× · OK ✓
Skimmer capacity, not skimmer marketing.
Gallons alone are not enough. ReefCrafter scales skimmer needs against your reef goal and livestock load, then calls out gear that is technically compatible but practically thin.
// skimmer_min = display_gal × bioload_factor
Heat that holds steady without becoming a risk.
Too little heater and the tank drifts. Too much and a stuck-on failure can cook the system. The engine checks wattage, tank size, and redundancy before the cart ever happens.
// 2.5 ≤ total_watts / display_gal ≤ 5.0
Flow and light matched to the animals.
A softie tank and an SPS tank should not buy the same equipment. ReefCrafter checks turnover, head loss, PAR targets, and coverage against the reef you are actually trying to keep.
// turnover = (return_gph × head_factor + Σ powerhead_gph) / display_gal
Why you can trust the planner
We'd rather show our work than ask you to take our word for it.
ReefCrafter is in open beta and the rule engine is a living document, not a finished verdict. Here is how it makes decisions, where it can be wrong, and how you can push back.
What it checks
23 explicit rules
Skimmer rating vs bioload, heater wattage band, light coverage, flow turnover by reef goal, return-pump head loss, ATO sizing, and more. Every finding shows the rule key, severity, and the inputs it pulled from your build.
2 errors · 13 warnings · 8 advisories
See every rule →
Where rules come from
Hobbyist math, not magic
Rules come from published manufacturer ratings, common reef-keeping benchmarks, and well-known community heuristics (the +1 skimmer rule, 2.5–5 W/gal heater band, 30× turnover for mixed reef). No machine learning, no scraped reviews.
Each finding cites the rule key and inputs it used
See the methodology →
How severity works
Errors block. Warnings don’t.
Errors flag real risk — undersized heater for tank size, missing core gear, hard physics. Warnings mean you’re at the edge of recommended specs. Advisories are community wisdom worth knowing. You can override warnings with a written reason; some safety rules can’t be silenced.
Severity is encoded per rule, not assigned by mood
See the key →
What it can’t do
It doesn’t replace judgment
The engine sees the gear you’ve added — not your room temperature, your water source, your maintenance habits, or every fish in our database. Treat findings as a pre-buy sanity check, not a guarantee. Cycling, husbandry, and acclimation still matter.
Beta · ruleset updates as we learn
See the limits →
Caught before you bought
Three findings the engine raises on real builds.
These are example rule outputs, not testimonials. Open the planner and the engine fires the same checks on whatever you build.
Heater wattage above safety ceilingheater_wattage_ceiling
A single 300 W heater on a 30 g tank exceeds the 5 W/gal ceiling. A stuck-on failure can cook livestock before you notice.
Fix: Split into two smaller heaters with a controller, or step down to ~125 W.
Skimmer rated below bioload targetskimmer_rating_medium_bioload
A skimmer rated for 60 g is fine on paper for a 40 g tank, but medium bioload tanks want at least 2× rated capacity.
Fix: Step up one model — the +1 rule from the community.
AIO + SPS goal flagged as harder pathaio_sps_advisory
All-in-one tanks with SPS-dominant goals work, but flow tuning, light coverage, and stability are noticeably harder.
Fix: Not a blocker. Plan for tighter parameter discipline and stronger light coverage.
Help us tighten the rules
See a rule that’s wrong, missing, or too aggressive?
We’d rather hear it from you than ship a rule that quietly steers someone toward bad gear. Suggestions are reviewed before anything changes — community input shapes the backlog, it doesn’t auto-publish.
- Suggest a rule. Tell us the gear, the goal, and the math behind your suggestion.
- Flag an edge case. Share a build the engine got wrong so we can scope the fix.
- Contribute experience. Long-running tanks teach the engine where the heuristics fail.
ReefCrafter is built and maintained by Max Rodes, a hobbyist — not a certified expert or a credentialed body. Suggestions are weighed against published specs, manufacturer data, and accepted reef-keeping practice before they ship.
Where to start
Start from where you actually are.
Three honest entry points. Pick the one that matches the question in your head right now — each ends in the same planner, just from a different door.
First reef
Planning your first tank.
Start from a vetted template that already passes the rules, then adjust the tank, livestock, and gear without losing the safety rails.
Existing tank
Already have gear.
Drop your tank, livestock, and current equipment into the planner. ReefCrafter flags what is undersized, mismatched, or missing redundancy.
Specific question
One thing is bothering you.
Skimmer too small? Light not strong enough? Flow not right? Each guide gives the direct answer, shows the math, then opens the full planner.
Vetted templates
Start from a reef that knows its limits.
Each template is a complete build that already passes the rules. Open it, see the math, then adjust the tank, livestock, and gear without losing the safety rails.
What you walk away with
A build you can actually buy from.
ReefCrafter is not a quiz. By the end, you have a saved plan with the parts list, the sizing math, the open risks, and a vendor path — yours to keep, share, or change later.
Saved build
One plan, all the parts.
Tank, livestock, lights, flow, heat, filtration, RO/DI — kept together so a change in one place updates the rest.
Sizing math
The numbers behind every choice.
Skimmer headroom, turnover, PAR coverage, heater wattage — shown against the target, not buried in a tooltip.
Risk list
Weak spots called out early.
Thin margins, mismatched goals, single-points-of-failure — flagged before the cart, with the next action you should take.
Vendor path
Buy where you want.
No ReefCrafter checkout. Outbound links to trusted vendors, clearly disclosed when affiliated. The recommendation has to make sense first.
Free, not shady
Premium planning. Still free.
ReefCrafter does not sell inventory, mark up gear, or lock you into one store. Vendor links may support the tool, but the recommendation has to make sense for the build first.
No checkout
You buy directly from vendors
Vendor-agnostic
The build decides, not the store
Affiliate transparent
Clearly disclosed, never hidden
Free to plan
No card, no gate, no pressure
Who’s behind this. ReefCrafter is built and maintained by Max Rodes, a hobbyist — not a credentialed body or a sponsored channel. The rule engine is deterministic and documented on the methodology page, the affiliate model is disclosed, and the planner is free because that’s the deal: you keep your money for gear, we keep our skin in the game.
Build once, regret less
The expensive part should be the tank, not the lesson.
Start with the reef you want. ReefCrafter will keep the parts honest, show the risks, and help you buy with a cleaner conscience when the build is ready.