The MOST Aquarium Freshwater Keeping INFO in 1 HOUR!

Summary

Lucas Bretz of LRB Aquatics presents a practical, experience-based approach to keeping freshwater aquariums “natural and simple.” His central idea is to create stable, biologically active environments and avoid unnecessary intervention. There is no single right setup: aquariums can use different substrates, lighting, plants, and filtration—or, in some cases, no filter—depending on the fish and the keeper’s goals.

Main ideas

• Prioritize stability and biological balance. Established aquariums can support bacteria, microorganisms, plants, algae, and small animals that help process waste and provide food. Bretz describes “dirty” tanks as potentially healthy when their biological systems are functioning well.
• Natural does not mean every tank needs plants or no maintenance. Plants can provide shelter, comfort, breeding sites, and nutrient uptake, but they are not mandatory in every aquarium. Water changes can also be helpful, particularly for growth; the right approach depends on the tank.
• Fish comfort affects behavior and breeding. Cover from floating plants, rocks, wood, and other structures can help fish feel safer. Larger groups may encourage more natural social behavior, while “dither fish” can help timid fish feel secure.
• Use natural materials where appropriate. Local soil or sand, leaves, rocks, and wood can reduce costs and create varied habitats. Materials may affect water chemistry, and rough lava rock may injure bottom-feeding fish such as Corydoras.
• Algae is expected, not necessarily a crisis. Bretz views algae as a normal part of aquatic systems and recommends managing it through sensible lighting, plant growth, and manual removal rather than trying to eliminate it entirely.
• Breeding can be supported by habitat and live food. Cover, microorganisms, places for eggs to settle, and—where suitable—small live foods such as daphnia and scuds can support breeding. Several low-intervention approaches are described below.
• Avoid reacting hastily to every problem. Repeatedly changing water conditions or dosing whole aquariums without a clear reason can cause problems. When appropriate, isolate an affected fish in a hospital tank, and remember that not every visible lump or illness has the same cause.

Practical approaches and methods

Choosing filtration

Bretz discusses hang-on-back filters, canister filters, sponge filters, air stones, and Matten filters.

• Reduce the force of water returning from a hang-on-back filter if it causes excessive splashing or surface disturbance.
• Canister filters may continue to provide useful biological filtration even when they appear dirty. Bretz presents this as his own experience, not as a general maintenance rule.
• Sponge filters can be hidden or partly buried. An airline can be directed through a cup lid to limit splashing.
• Use only as much aeration from air stones as needed; Bretz advises against making the tank excessively turbulent.
• Matten filters can be effective for breeding and retaining microorganisms, but take up substantial tank space.
• Bretz discourages using clams as a filtration solution, saying they can be difficult to feed and may cause problems if they die.

Selecting and preparing substrate

• Untreated local soil or sand may be an inexpensive option. Bretz describes removing the surface layer, spreading the material out, and letting it dry in sunlight before use.
• Commercial substrates vary. Some are acidic and may suit certain planted or soft-water setups, while others may be better suited to harder water.
• Keep layered substrates relatively simple—roughly two or three layers. One option is a thin nutrient-rich clay layer capped with sand, gravel, or another substrate.
• Consider both the substrate’s effects on water and whether sharp or abrasive material could harm fish.

Designing hardscape and cover

Use wood, rocks, leaves, and plants to create hiding places, break up lines of sight, and add depth. For a more natural-looking aquascape, vary rock sizes gradually rather than using only one size.

Bretz suggests testing rocks by scratching them against concrete: rocks that leave a mark may break down more readily and add minerals to the water. He ties plants to wood with thread, which he finds easier to remove or replace than glue. In tanks with digging fish, secure plants among rocks or otherwise protect them with the hardscape.

Managing lighting, plants, and algae

• Match light intensity to plant density and aquarium depth. Bretz says many tanks receive more light than their plants need.
• If algae becomes a problem, consider a shorter or dimmer lighting schedule. Some attractive aquascapes receive about five hours of light, while other setups may use longer periods.
• Ambient room light or carefully controlled natural sunlight may be enough for some tanks, though sunlight can also cause green water.
• Remove excess algae manually when needed. Bretz suggests doing this before a water change so loosened material can be removed.
• Encourage healthy plant growth rather than focusing only on algae removal. Plants compete with algae for nutrients, and some plants may inhibit or benefit other plants.
• Floating plants can provide overhead cover, which may reduce fish stress and reveal more natural social behavior.
• Suitable plants can be allowed to grow above the waterline, where some may flower or grow more vigorously.

Using tank organisms as part of the ecosystem

Snails, shrimp, scuds, and worms can consume decaying material or serve as food for fish. Daphnia can help clear green or cloudy water when fish are not eating them, and Bretz uses their presence to encourage breeding in some fish.

He recommends caution with plecos in breeding tanks because they may eat eggs. He describes Siamese algae eaters as useful when small, though they may eat less algae as they grow. He also mentions Corydoras for stirring and sifting substrate. “Cleaner fish” should not be treated as a substitute for addressing the underlying cause of a maintenance problem.

Breeding strategies

• “Musical fish”: Keep a breeding group in one aquarium for several weeks, then move the adults and leave the original tank undisturbed so eggs or fry can develop.
• Spawning mops: Use these when eggs need to be collected and transferred to a separate container.
• Rock piles: Arrange rocks to create crevices where egg-scattering fish can deposit eggs. The gaps also give fry shelter and access to microorganisms.
• Mesh breeding baskets: Place a group of fish in a floating mesh basket, with cover above them to help them feel secure. Bretz says eggs can fall through, allowing fry to grow in the main tank.
• Community breeding: Some fish can reproduce in community aquariums if the setup provides suitable cover and the adults cannot consume all the young.
• Frequent feeding: For some species, feeding more often may reduce predation on fry and make them easier to collect. Feeding practices must still suit the aquarium’s capacity to handle waste.

Water changes and parameters

Bretz says small, regular water changes can support fish and plant growth, while less frequent changes may preserve a more stable system and reduce disturbance. He does not recommend one schedule for all tanks. He also suggests choosing a larger or smaller siphon hose depending on whether speed or detailed cleaning is the priority.

Water conditions in nature vary with rainfall, seasons, and decaying leaves, so keepers should not assume a species always encounters one fixed set of parameters. Bretz personally emphasizes measuring total dissolved solids (TDS) and describes using it to guide his shrimp keeping. His discussion of TDS as a way to distinguish acidity from alkalinity is a personal claim, not a reliable replacement for measuring pH, hardness, or other relevant water conditions.

Handling fish health issues

Bretz advises against “nuking” a whole tank with medication when the problem may be limited to one fish. When feasible, he suggests using a hospital tank.

During the Q&A, he names medications he has used for suspected wasting disease or internal parasites and gives an example of a treatment approach for worms. These are his remarks, not individualized veterinary guidance. Medication choice and dosing should follow the product’s instructions or advice from an aquatic veterinarian.

Audience Q&A and closing

Audience members ask about parasites, heating a fish room, planted tanks that receive attention only once or twice a month, and how to persuade a partner to allow more aquariums. For less frequently attended planted tanks, Bretz suggests using organisms that consume decaying material. For heating, he describes warming the room and placing heaters strategically in lower tanks so heat can rise.

He also shares that the hobby has helped him build a livelihood and spend time with his child. The talk ends with him giving away easy-to-grow plants that he says were raised without fertilizer or added CO₂.

Speakers and sources featured

• Lucas Bretz (LRB Aquatics): Main speaker and source of the aquarium-keeping advice and personal experiences.
• Audience members: Unnamed attendees ask questions and offer comments; one attendee is addressed as Brandy.
• Hiko Blair: Referenced by Bretz as an author of books about aquatic waterways and biotopes; not a speaker in the subtitles.