# Glass & Gravel - full reference Betta and nano tanks, exhaustively - the desk tank done right. https://glassandgravel.com Published by Slate Mill Group. Contact: info@glassandgravel.com Author: Scooter M., enthusiast. -------------------------------------------------------------------------- ABOUT THIS SITE -------------------------------------------------------------------------- Glass & Gravel covers freshwater betta and nano aquariums - the desk-scale tank. It is written for a reader who wants the specific number rather than a range: what wattage, how much flow, how many gallons, what dose. Its distinguishing characteristic is that it publishes the arithmetic behind every recommendation instead of claiming hands-on testing. WHAT WE EXPLICITLY DO NOT CLAIM: - That we tested any product. Units we claim to have tested: zero. There is no test bench, no lab, and no drawer of samples. Every page states this. - Any credential we do not hold. No veterinary qualification, no expert panel. - Tenure in the hobby. - Any number we cannot source to a published document or compute from one. WHAT WE DO INSTEAD: - Read manufacturer documentation and link to the exact page each figure came from. - Record what each manufacturer declines to publish. In this category that is frequent and is itself a finding: no nano filter publishes a flow rate, no nano light publishes PAR, and several kits publish no pump output. - Compute what the published figures imply for a specific tank at a specific room temperature, and print the sum on the page. SCOPE: freshwater only. No saltwater, no nano reef. No livestock links. No illness diagnosis and no medication recommendations. -------------------------------------------------------------------------- THE ARITHMETIC, IN FULL -------------------------------------------------------------------------- WATER VOLUME Assumption (stated, not a manufacturer figure): substrate, hardscape and the fill line take about 15% of a tank's rated volume. Rated 3 gal -> 2.6 gal of water Rated 5 gal -> 4.3 gal of water Rated 10 gal -> 8.5 gal of water Rated 20 gal -> 17 gal of water Every wattage, turnover and dose on the site is computed from actual water volume, never from the shelf label. HEATER WATTAGE Watts = actual water gallons x 0.35 x (target degF - coldest room degF) The 0.35 constant is derived from Fluval's published P Series ratings. Fluval rates each heater to a capacity and separately publishes that a lift over 12 degF above ambient requires additional heating capacity, which makes each rating a triple: P10 10W to 3 US gal -> 10 / (3 x 12) = 0.278 W/gal/degF P25 25W to 6 US gal -> 25 / (6 x 12) = 0.347 W/gal/degF P50 50W to 15 US gal -> 50 / (15 x 12) = 0.278 W/gal/degF We use 0.35, the largest of the three, because undersizing a heater is the failure that kills fish and oversizing one only makes it cycle more often. Target temperature: 78 degF, inside the 76-82 keeping range with margin. Sizing is against the COLDEST the room reaches, not its average. Worked results at a 68 degF room: 3 gal -> 9.1W required -> buy 10W 5 gal -> 15.1W required -> buy 25W 10 gal -> 29.7W required -> buy 50W 20 gal -> 59.5W required -> buy 75W FILTER TURNOVER Target GPH = actual water gallons x 4, ceiling x 6. The general aquarium convention is 4-6 turnovers per hour. For a betta we take the bottom of that range: a long-finned fish in a small water column cannot swim out of the current. 5 gal rated -> about 17 GPH target, 26 GPH ceiling. For context, the Fluval Spec V's published pump output of 55-80 GPH is 13-19 turnovers an hour in that tank. DOSING (converted from published directions) Seachem Prime: published 5 mL per 200 L / 50 US gal of new water. 5 gal rated, full fill -> 0.43 mL 5 gal rated, 50% change -> 0.21 mL Seachem Stability: published 5 mL per 40 L / 10 US gal on day one, then 5 mL per 80 L / 20 US gal daily for seven days. 5 gal rated -> 2.13 mL day one, 1.06 mL daily thereafter. Doses at nano scale are fractions of a milliliter. Use a syringe, not the cap. SUBSTRATE QUANTITY Fluval publishes: kg = length(cm) x width(cm) x depth(cm) / 1000. Fluval Spec V footprint (19.5 x 6.5 in) at 1 in deep -> 2.1 kg / 4.6 lb. Standard 10-gallon (20 x 10 in) at 1 in -> 3.3 kg / 7.2 lb. -------------------------------------------------------------------------- POSITIONS THIS SITE TAKES -------------------------------------------------------------------------- TANK SIZE. Minimum for one betta is 5 US gallons rated. The reason is buffer, not swimming room: ammonia concentration, temperature stability and margin for error all scale directly with water volume. Ten gallons is materially better and usually costs under twenty dollars more once heater, filter, light and substrate are accounted for, since those cost the same either way. HEATERS. A betta needs one in essentially every American home. Published preference is around 80 degF; US room temperatures are commonly 67-69 degF. A chronically cold betta is lethargic, eats less and has suppressed immune function, so what people usually notice is a secondary infection weeks later that never gets attributed to temperature. FLOW. Almost every nano filter pushes three to five times the turnover a betta wants. The fix is mechanical and takes ten minutes: coarse filter foam over the outflow, or a spray bar. Never restrict the intake - that starves the media of the oxygenated flow the bacteria need. STOCKING. Decided by volume, and the threshold is stated before any species list on every page in that section: Under 5 gal - nothing; the tank is below our floor for the betta alone. 5 gal - invertebrates only. One nerite snail, or two or three Amano shrimp, with dense cover. No fish of any species. 10 gal - fish become possible. One properly sized group of one species. 20 gal - a community tank that contains a betta. A betta needs no tank mates at all. It is solitary and territorial, does not shoal and does not pair-bond. Tank mates are something the keeper wants. Most popular five-gallon tank mate suggestions fail because the species shoals and needs six of its own kind, which is a welfare failure independent of the betta's behavior. BOWLS. Bettas have a labyrinth organ and take oxygen from the air, so a bowl does not suffocate them. That true fact answers a question nobody was asking. What kills a bowl-kept betta is ammonia with no filtration to process it and cold with no room for a heater, over months. Published lifespan is three to five years from hatching, and shop fish are typically 6-12 months old at purchase. CYCLING. Three to six weeks before the fish. No product removes the wait; bottled bacteria shortens it, and Seachem publishes a seven-day schedule for Stability rather than a one-day one. The tank is cycled when a 2 ppm ammonia dose processes to zero ammonia and zero nitrite within 24 hours. FEEDING. Two or three granules once a day. A betta's stomach is roughly the size of its eye. Overfeeding causes an ammonia load, constipation and bloating, and a pest snail population explosion simultaneously. PLANTS. Anubias and java fern tied to hardscape are the answer to almost every low-tech betta tank. Aquarium Co-Op publishes both as low light with no CO2 requirement; Anubias Nana Petite is published at 10-20 PAR. Never bury the rhizome - that is the most common way people kill both. Carpeting plants need high light and usually CO2 and will fail in a low-tech nano. LIGHT. Photoperiod matters more than output. Eight hours on a timer. If you have algae with healthy plants, cut to six hours before changing anything else. -------------------------------------------------------------------------- PRODUCTS AND SOURCING -------------------------------------------------------------------------- The product registry is deliberately short because we only list products whose specifications we can trace to a published document. Every entry carries a "skip this if" line as a required field. Manufacturer sources relied on: Fluval - tank kits (Spec, Flex), P Series heaters, Nano filter, AquaClear power filters, Stratum substrate, Plant 3.0 Nano LED, Bug Bites food. Seachem - Prime, Stability, Flourite Black Sand (which publishes a full laboratory mineral analysis, method named, run by the University of Georgia Chemical Analysis Lab). Aquarium Co-Op - published plant care requirements and betta care guidance. Absences recorded rather than filled: No nano filter in the registry publishes a flow rate. No nano light publishes PAR at any depth. The Fluval Flex 9 publishes no pump output. Sponge filters have no manufacturer and no published specification of any kind. We could not reach an Aqueon-hosted specification page for the Pro heater. PRICES. Shown only from a live data layer with the retrieval date beside them. If that data is more than 48 hours old every price disappears automatically and buttons revert to "check price on Amazon". No stale, remembered or estimated price appears anywhere. At the time of writing this instance holds no live price data, so every button reads "check price" - which is the system working. SCORES. Every product carries an editorial score out of 10, weighted heavily toward what the manufacturer is willing to publish and toward suitability for a betta specifically. Those scores are ours and judgmental, they are labeled as such, and they NEVER appear in the site's structured data. Publishing an editorial score as machine-readable review markup would assert a review we did not conduct. The JSON-LD carries Product and Offer nodes only. -------------------------------------------------------------------------- HOW THIS SITE IS FUNDED -------------------------------------------------------------------------- Amazon Associates affiliate commission, and nothing else. No subscription, no display advertising, no sponsorship, no paid placement, no free product. Every outbound commercial link routes through /go/ on this domain, carries rel="sponsored nofollow", is marked #ad, and links to the disclosure page. The /go/ routes are noindex, robots-disallowed and excluded from the sitemap. A commission never moves a ranking. Several of the strongest recommendations on this site pay little or nothing: a plain ten-gallon glass tank rather than a designer five-gallon kit, a sponge filter as the cheapest correct filtration, feeding less, and turning the light down. We do not link to live animals and would not if a marketplace made it easy. This makes the stocking section the least profitable part of the site. -------------------------------------------------------------------------- WHAT THIS SITE CANNOT TELL YOU -------------------------------------------------------------------------- Stated on the methodology page and repeated at the foot of individual pages: - Whether a heater holds calibration after a year, or which brand sticks on. - How loud a pump is in a room, or how equipment ages. - Whether a plant will grow in your specific water. - Whether an individual betta will accept a tank mate. Temperament varies and no research substitutes for having somewhere to move the animal if it fails. - How to treat a sick fish. We do not diagnose and do not recommend medication. -------------------------------------------------------------------------- COMPLETE PAGE LIST -------------------------------------------------------------------------- HOME https://glassandgravel.com/ TANKS & KITS - https://glassandgravel.com/tanks /tanks/how-many-gallons-does-a-betta-need /tanks/best-betta-fish-tanks /tanks/best-nano-tanks /tanks/best-small-tanks-for-beginners /tanks/fluval-spec-v-review /tanks/fluval-spec-v-vs-flex-9 /tanks/betta-tank-setup-guide /tanks/betta-bowls-what-to-know HEATERS & TEMPERATURE - https://glassandgravel.com/heaters /heaters/what-size-heater-for-your-tank /heaters/best-nano-tank-heaters /heaters/best-heater-for-a-5-gallon-betta-tank /heaters/best-heater-for-a-3-gallon-tank /heaters/do-bettas-need-a-heater /heaters/betta-water-temperature /heaters/preset-vs-adjustable-heaters FILTERS & FLOW - https://glassandgravel.com/filters /filters/do-betta-fish-need-a-filter /filters/best-nano-tank-filters /filters/best-sponge-filters-for-betta-tanks /filters/best-filter-for-a-5-gallon-betta-tank /filters/sponge-filter-vs-hang-on-back /filters/how-to-baffle-a-betta-filter STOCKING & TANK MATES - https://glassandgravel.com/stocking /stocking/betta-tank-mates /stocking/best-betta-tank-mates /stocking/best-nano-fish /stocking/betta-tank-mates-5-gallon /stocking/betta-tank-mates-10-gallon /stocking/betta-and-shrimp /stocking/betta-and-snails /stocking/betta-vs-guppy PLANTS, SUBSTRATE & LIGHT - https://glassandgravel.com/plants /plants/best-betta-plants /plants/best-betta-substrate /plants/best-nano-tank-lights /plants/aquasoil-vs-inert-substrate /plants/planted-nano-tank-light-requirements /plants/how-to-aquascape-a-5-gallon-tank CARE & MAINTENANCE - https://glassandgravel.com/care /care/betta-fish-care /care/how-to-cycle-a-betta-tank /care/best-betta-food /care/betta-tank-cleaning-schedule /care/betta-fish-lifespan /care/pellets-vs-flakes-vs-frozen TRUST, LEGAL AND UTILITY https://glassandgravel.com/about https://glassandgravel.com/methodology https://glassandgravel.com/editorial-policy https://glassandgravel.com/faq https://glassandgravel.com/disclosure https://glassandgravel.com/contact https://glassandgravel.com/privacy https://glassandgravel.com/terms https://glassandgravel.com/site-index MACHINE-READABLE https://glassandgravel.com/sitemap.xml https://glassandgravel.com/feed.xml https://glassandgravel.com/robots.txt https://glassandgravel.com/llms.txt https://glassandgravel.com/llms-full.txt