Multi-tank or Rack Systems
This guide is designed to help align your tank design or fish system in your fish rooms and vivariam with your research goals.
When applicable, I will show photo examples or link similar products to what I describe. Use any supplier for your purchase to get the best product for you at the best price you can find. Most products come from many suppliers and many supplisers have similar items. This includes and is not limited to entire aquatic systems, aquarium salts, system pumps, air pumps, filtration socks, pleated filters, nets, bacteria dosing, water quality testing kits and methods, pellets and food, and beyond.
Our university also set up a business Amazon account for each lab to work with our tax-free status.
System Type: Open System
We do not see open systems often in the research world, but there is a time and place. This is a brief introduction.
Flow in and flow out
When a research system is near a water source—by the ocean, estuary, or freshwater source needed for your fish—, you can draw water directly from your source for your tank. You will need multiple types of filtration and UV sterilization before using the water. These systems then release tank water back into the source.
Pros of this type of system:
Continual water exchange removes wastes in the water column and replaces nutrients found in the native water
Can maintain temperature with the natural habitat allowing for seasonality
Cons of this type of system:
Introduction of pathogens in forms of viruses or bacteria found in the water that cannot be filtered or removed (or guaranteed to be removed)
Likely to introduce outside animals and parasites in the forms of eggs or plankton
Water may get too warm for experiments or for your research fish (or you cannot have a prolonged temperature experiment if you need the fish to stay consistent, colder or warmer, for months to years)
You cannot use treatments, additives, or chemicals in your research that could damage the ecosystem when the water returns
These systems are wonderful if in the right location and all your water needs are present. They are not the best for research because the water parameters you get from the source water could be too variable day-to-day as well as the potential introduction of pathogens and microorganisms.
System Type: Closed System
Closed systems include individualized tanks or rack system for your research animals. “Closed” refers to the fact that water does not enter and leave the system from an outside, unmanaged source. They are either isolated ecosystems, about 20 to 60 gallons total, or share water between all tanks in the system which can be thousands of liters (hundreds of gallons) at once.
Individual tank systems
Needs for individual tank system
10 to 20 gallon tanks (could be larger, but the larger the tank, the heavier and stronger the support needs to be)
Side-mount filtration pump or external canister pumps
Hanging filtration can be purely mechanical filtration and flow, but can have activate carbon filtration pads and can also have space for biological filtration such as ceramic rings
External canister pumps have space for mechanical and biological filtration as well as add a large percentage of water into the entire system with their size and capacity
Hides and/or submerging plants for fish ecosystem and enrichment (easy to sanitize and clean or remove and disguard between fish populations)
Floating bioballs for surface area for bacteria and biological filtration
Airstone and airpump for each system or a pump with enough ports for the number of tanks in your experiment
Aeration is a redundancy since water is oxygenated with the falling water from filtration return in side-mount pumps, but it is necessary to have the redundancy in case your filtration pump malfunctions between technician visits
Pros of individual tanks:
You can vary the parameters very easily between tanks such as:
conductivity or salinity
water temperatures
pH—acidic or basic
treatments such as medications, bacteria colonies, or germ-free
A small number of population variables
Ease in catching or monitoring fish from most sides
rack systems prohibit viewing fish tanks from all sides except one and this is usually the short side of the tank. Racks can also prevent ease in looking over the top of the tank if the rack distance above the tanks is smaller than you can fit into
Space efficient if you do not have entire rooms to dedicate to a rack system
Easy to change parameters for fish or perform a complete water change to remove and restore to basic parameters
Cons of individual tanks:
Each tank is its own ecosystem—you have to build the biological filtration on every tank on its own and ensure the water quality is good with all tanks
Between each water change, maintaining treatment parameters is more difficult
If you need a week straight of a certain parameter level, that is difficult to maintain with the need to siphon food and waste from the system to prevent spikes in nitrogenous waste. Even with a cycled system, smaller volumes are impacted by fish, waste, and dead animals (if not found and removed immediately)
Each system could have its own barrel of parameter-correct water, but that requires space and extra resources
Research populations are limited to the number of tanks you have running at once
Multi-tank or Rack systems
The larger rack systems should include:
Multiple tanks for fish
One or more “sumps"—water wells at the bottom of the system that hold extra water for biological and mechanical filtration and aid in aeration
Pipes connecting the sump with return flow to all tanks
UltraViolet (UV) sterilization
In-line canisters where you can add chemical filtration like activated carbon or Marineland Zeolite—crystals designed to help remove ammonia and prevents spikes in ammonia designed for freshwater systems
Air pump with tubing for aeration to all tanks
Censors and display for constant parameter monitoring
Dosing vats connected to censors to maintain pH and conductivity/salinity at a specified level in the system
This is a single rack system
This shows Iwaki’s single-rack system. It has smaller, individual tanks and larger small-population tanks; dosing vats and pumps along the right side; the sump at the bottom holding bioballs (biological filtration), optional heater, and filter socks (first stage of mechanical filtration); two canisters for filtration and activated carbon (bottom left); UV sterilization (silver tubing on the outside lower left); probes and sensors with a screen display (top left); aeration pump, airlines, and airstones to each tank; and the pump and PVC pipe returning water from the filtration back to the tanks.
Building your own rack system
When you build your own rack system, a lot of variables some into play.
The science behind pump dynamics, head pressure, and more all come into play when ensuring a system works, but selecting the correct parts and pieces can be a nightmare if you are unprepared for the task.
Most importantly, you need to know how many tanks and how high the rack system will be to know what your pump will need to supply. Luckily, places like Pentair have a Pump Calculator to help determine which pump fits your need. Calculators require information suck as the height the water will have to flow (to reach your highest tanks), the diameter of the pipes you use for tank return, and the distance away for your furthest tanks. You can also look at pumps based on maximum pressure, maximum pressure ft of head, maximum flow rate (GPM or LPM), horsepower, inlet/outlet size for tubing, and more.
Pump Calculator Specifications
This shows most of the type of information required to determine the pump required. There are diagrams online to define the Specifications further.
To know how many tanks needed is one step. The distance from sump to tanks, height pumps have to push past the surface of the highest tank, any 45˚ or 90˚ corners the water will have to navigate, and specifications about your PVC size are also vital pieces to determine pumps needed for your system.
Additionally, pumps for aeration, pumps and pipes for moving water from your storage vat to tanks, sumps or towers for biological filtration and mechanical filtration, and UV filtration need space around your fish room as well.
Censors for water chemistry do not have to monitor 24 hours a day. You can use a hand-held unit daily to ensure temperature, pH, conductivity/salinity, and dissolved oxygen are maintained throughout the system. There are a variety of submergible censors you can attach to your system that link to wifi or data cables to view data throughout the day and send alerts when parameters are out of range.
Large 50-gallon (190 L) trash cans on wheels are a great option for making system water when you perform water changes and system maintenance. A submergible magdrive pump is useful for refilling systems as well. This requires hosing as well from the barrel to the system.
Have the professional build your system..
There are a few different aquatic system manufacturers who build rack systems with everything included and needed. This are large budget items and often require quotes from multiple suppliers for the level of spending they would include. Also, you may have to plan an extra $100,000 or more to build fish rooms and purchase start-up supplies outside of the normal filtration and fish food needed for normal function.
Here are a few examples of companies of many where you can get a quote for a complete research animal system. At our university, you have to have three quotes with capital expenditures as expensive as finishing a fish care and research room.