📊 Original data reference
Reefkeeping, by the numbers
We analysed 4,495 real records — Reddit posts, comments and search autocomplete — from the saltwater & reef community to find what keepers actually ask and worry about. The short version: they chase corals, but it's the water chemistry that keeps them alive. Here's the data, and what it means.
Updated September 2026 · method & limitations below
4,495records analysed
3data sources (Reddit + search)
14care topics ranked
1,285mentions of the #1 topic (corals)
3,460mentions across the top 4 topics
14/14top topics with a Coralkin guide or tool
What the data says
- Corals are the whole conversation. The single most-discussed topic is corals — SPS, LPS, softies and fragging — with 1,285 mentions, far ahead of anything else. Reefkeeping is coral-keeping for most of the community.
- But chemistry is what actually decides it. Water chemistry & parameters — alkalinity, calcium, magnesium, salinity, dosing — comes second (874 mentions). Corals live or die on the numbers, which is why we put calculators behind the guides.
- The top four are the reef itself. Corals, chemistry, fish stocking and algae/pests together drew 3,460 mentions — the core loop of choosing livestock, keeping the water right, and fighting back nuisance algae.
- "Is this hobby a money pit?" is a real, ranked worry. Cost / budget / "money pit" (256 mentions) outranks even disease — the fear of expense is one of saltwater's biggest gatekeepers, and one we answer head-on.
- We answer all of it. Every one of the top 14 topics maps to a fact-checked Coralkin guide or free tool — coverage driven by real demand, not guesswork.
The 14 most-discussed topics
Records whose text mentions each topic, across all mined reef text. Each links to the Coralkin guide or tool that answers it.
The corpus, by source
Where the 4,495 records came from — 3,170 posts, 1,095 comments and 230 search-autocomplete phrases. We count only records that carry text, so the corpus we cite is the corpus we scanned.
| Source | Posts | Comments | Autocomplete | Total |
|---|---|---|---|---|
| r/ReefTank (Reddit) | 1,774 | 1,095 | — | 2,869 |
| r/Aquariums (Reddit) | 1,396 | — | — | 1,396 |
| Amazon search-autocomplete | — | — | 230 | 230 |
| All sources | 3,170 | 1,095 | 230 | 4,495 |
Method & limitations
- Source: real posts, comments and search-autocomplete phrases mined from the saltwater/reef community (r/ReefTank and r/Aquariums on Reddit, plus Amazon "reef tank" search autocomplete).
- Sample size: 4,495 records (3,170 posts, 1,095 comments, 230 autocomplete phrases). We exclude empty records — a record only counts if it carries text.
- Window: compiled September 2026 from our standing mined corpus. Exact per-record dates aren't tracked at this aggregate level, so we don't claim a precise date range.
- Method: topic-keyword frequency counts — we grouped the text by care topic and counted how many records mention each. This is a simple keyword grouping, not sentiment analysis or machine clustering, and we won't dress it up as more than that.
- Limitations: a mention isn't a unique person, and one record can mention several topics, so treat the ranking as the robust signal rather than any single number. The corpus also carries some cross-post and meme noise (r/Aquariums is a general community), which is why we lead with the aggregate topic ranking, not individual quotes. It's a demand signal — what to write about — never a source of care facts (those come from our cited authorities).
Cite this
Free to cite or link, with attribution:
Coralkin (2026). What Saltwater & Reef Keepers Actually Ask: an analysis of 4,495 reef-hobby records. https://coralkin.com/reef-keeping-by-the-numbers/