Aquarium Co-Op (YouTube channel)
by Cory McElroy · Aquarium Co-Op
Cory McElroy's long-running video channel on freshwater fishkeeping. It covers tank setup, cycling, filtration, stocking choices, easy live plants, low-tech planted tanks, and diagnosing and treating common fish diseases, all shown on working tanks. This is the best free visual on-ramp for someone setting up a first tank. It is a store-owned channel, so viewers should skip past the product plugs.
More resources on Fishkeeping & Aquariums
Management of Aquarium Fish (MSD/Merck Veterinary Manual)
This is the authoritative free source for the disease part of the topic. It replaces a scattered set of forum threads and single-disease sheets with one structured chapter plus linked sibling chapters on bacterial, parasitic and viral diseases. A veterinary reference chapter on keeping aquarium fish healthy. It covers history-taking, diagnostic techniques, treatment and regulatory limits on drugs, quarantine and biosecurity for home aquariums, and common water-quality problems, with linked chapters on bacterial, parasitic and viral fish diseases.
Ammonia in Aquatic Systems (UF/IFAS FA16)
A University of Florida extension fact sheet on the nitrogen cycle. It explains how bacteria convert ammonia to nitrite and then nitrate, why un-ionized ammonia is far more toxic, how pH and temperature shift toxicity (with a lookup table), and how to test and control ammonia. This is a primary, institutional source for the chemistry behind cycling, which hobby guides only paraphrase. It is free and short, and the pH/temperature toxicity table is the key piece most beginner sources skip. It is written for ponds and aquaculture as well, but the chemistry carries over directly to aquariums.
Ecology of the Planted Aquarium
This is the definitive text for the planted and low-tech part of the topic, backed by hundreds of citations to primary research. A book that uses the scientific literature to explain how planted aquariums work as ecosystems. Topics include plant nitrogen uptake versus bacterial nitrification, soil substrates, allelopathy, CO2 and nutrient dynamics, and the low-tech 'Walstad method' of soil-based tanks with little filtration.
The Simple Guide to Freshwater Aquariums (2nd Edition)
This is the standard single-volume beginner text. It is organized around the husbandry principles that prevent common failures, so it works as a structural foundation rather than a species catalog. A 256-page freshwater aquarium manual from T.F.H. (2009). It covers tank and equipment choice, biological filtration and cycling, water changes, compatible stocking, feeding, and routine maintenance, and stresses avoiding the beginner mistakes that most often kill fish.