Aquariums/Tanks

Dr. Craig Kasper

• Many people have owned or will own a fish tank (it may even contain fish)

• As we will see, aquariums for fish take on many forms...some are simple.

• Some are a bit more complex...

Aquariums: What are they?

• An

aquarium

aquaria

) (plural

aquariums

or • Clear-sided container • Typically glass or high-strength plastic • Houses plants and animals, or both.

• Private and public display

• Aquarium keeping is a popular hobby (>60 million hobbist globally) • Recognized as early as the1850s, when the predecessor of the modern aquarium was first developed as a novel curiosity, • Public aquaria reproduce the home aquarist's hobby on a grand scale — the Osaka Aquarium (seen here), boasts a tank of 1.4 million gallons and nearly 580 spp.

• Currently, huge variety exists!

• A simple bowl housing a single fish to complex simulated ecosystems with carefully engineered support systems.

• Fresh or salt water, tropical or cold water.

• Wild collecting still an issue, esp. salt H 2 0 (REM:ornamental fish?) The Florida Aquarium

• Must maintain a tank ecology that mimics natural habitat.

• Controlling water quality ! managing the inflow and outflow of nutrients, management of waste (nitrogenous) beneficial bacteria populations.

Aquarium Parts

• Tank • Filter • Gravel/sustrate • Pump • Aerator • Reliable water supply

Tanks

• High quality glass -Plexiglass is expensive, but lighter Monteray Bay Aquarium

Plexiglass offers unique design options!

No one wants this much water on the carpet!!

Courtesy: Perigrine Plastics

Production Tanks

• Production tanks can be made of fiberglass, wood, etc.

• Volume necessary and strength, not aesthetics!

St. Croix Waters Fishery

Mote Marine Laboratory

Mote Marine Laboratory

Filters

• Primary method of cleaning tank • Removes solids small solids called “suspended solids” larger ones called “flocs” • Provides substrate for nitrifiers • Many types depending on needs

Gravel/Substrate

• Material for nesting • Aesthetics • Nitrification • “Live sand” • Filtration

Gravel/Substrate

PVC shavings!

Gravel/Substrate

Activated Carbon

Media Filters

• Bead/Sand/Media filters all use water pressure to force water through some type of media. • Excellent filtering capacity, esp. for larger systems • More maintenance (media changing backwashing, etc.)

Mixed media filters

Gravity Filtration

• Trickle filters/Settling Chamber/Swirl Separators • Most use gravity to accomplish filtering.

• Better for nitrification and oxygenation.

• Prone to clogging if primary filtration inefficient.

Screen Filters (RDF)

• Screen/Microscreen filters • A.k.a.—rotating drum filters • Utilize large particle size “flocculation” to remove solids. • Excessive flow can reduce efficiency!

Best of Both Worlds??

• “Fluidized” bed?? • Actually more simple than it sounds.

• Running a sandfilter backwards would give same effect.

• Huge potential for nitrification.

• Bed expansion by optimizing flow.

Fluidized-Bed Filter • Media maintained ~ 50-100% expansion volume of original.

Over 20 feet tall!

Bead Filters

• Another form of “fluidized” filter system (upwelling). • Media is usually plastic beads. • Good nitrification.

• Performs poorly during heavy loading.

-excessive stocking density -ad libitum feeding

Aeration

• Oxygen • Speeds up decomposition • Circulates water (air lift pump)

Aeration

Non-pressurized Downflow bubble contactor (DBC) Counter current diffusion column U-tube diffusers

DBC U-tube

Biofilters

•Help to establish nitrogen cycle.

•Break down toxic fish wastes.

Liquid Oxygen • Facilitates higher densities • Cheaper than gas O 2 • Increase O 2 saturation • Can increase CO 2 levels • False security?

-increased density -increased solids -may increase disease Ozone • Increases flocculation • Reduces disease outbreak -kills bateria, fungus, viruses • Expensive!!

Protein Skimmers/ Foam Fractionators • Removal of excessive organics -decreases B.O.D. and C.O.D.

• Increases flocculation -decreases solids -increases water clarity

• What really does the work??

Bacteria!!

How Do I Condition a Biofilter?

• Since nitrifying bacteria are ubiquitous (everywhere) and can be found easily in the water column, soil and sediments you can just add some pond water or a little dirt to the system. (Could introduce pathogens or other toxins though.) • A better way… a. Use existing media from another filter as a starter colony (just like passing around grandma’s sour dough starters).

Recipe for Nitrification Success!

• Once you’ve achieved proper ph, hardness, and alkalinity for your target species; it’s time to add the bacteria before you stock out.

• System start-up formulae: a. Spike the system with ammonia.

-(NH 4 )SO 4 -NH 4 Cl 3.3 ppm (mg/L) 3-6 ppm (mg/L) b. Place several fish in the system and feed them.

Wait 4 weeks (if no starters present)…presto!

Get ‘em yourself!

(Sewage treatment inspectors get top pay!!)