Display Tank

DQI – initial planning and project management for the design and installation of the Display Tank

ATM – tank builder. Tank trucked 2000 miles on a flat-bed from Las Vegas to Oakville near Toronto.

Display Tank Specs
– Acrylic – L-shaped
– Short end is 8′ long x 3′ wide x 2.5′ tall.
– Long end is 16′ long x 3′ wide x 2.5′ tall.
– Euro-braced around top.
– Sides are 1″ thick except 16′ panel which is 1.5″ thick.
– Stand is tubular steel.
– All sides are viewable except the ends where the overflows are located.

The tank is enclosed at the top with its own circulation fan to ensure that the tank and home perform as two separate climate zones, each with their own independent HVAC systems. A galvanized metal duct runs over the length of the tank and a large fan pulls heat and humidity directly into the Fish Room, maintaining negative pressure over the tank.

Display Tank Fan

Display Tank Fan

The substrate is a mixture of medium and coarse sizes and textures of aragonite to a depth of approximately 2″. This provides a more natural substrate that isn’t all white or all the same size. It seems to allow for more healthy reef nutrition for the various lifeforms that propagate naturally in this type of substrate. It is much better than fine sand in my opinion on several levels. Gobies love it, jawfish are in heaven and the shrimp-fish are fat and happy feeding regularly off it.

The live rock started with a 1500 lb. shipment of Jakarta premium rock, including 200 lb. shelf rock and 500 lb. Fiji rock, shipped overnight direct. This was treated constantly for a period of six months owing to many delays in the original build. The rock was assembled into shapes and patterns influenced by the Four Masters that this tank is named after.

Live rock

The rock shapes are held together with EpoPutty.


EpoPutty - We are impressed!

EpoPutty is a two-part epoxy adhesive that can be applied and left to set under water. It comes in 100 and 500 gram packages. Wearing rubber or polyethelene gloves, take small, equal amounts of resin and hardener and wet them in saltwater. Work the two thoroughly until they are well mixed. Apply within 30 minutes either in or out of water. Allow 4-5 hours to set. Note that EpoPutty will hold two surfaces pressed together by gravity, but will not hold two surfaces that are pulling away from each other. In that case you must bind the two surfaces together until the adhesive sets.


tank delivery

The Display Tank as first delivered

Display Tank - Current

The Display Tank today


Display Tank Lighting

The lighting currently consists of two rows of Orphek PR-156s running down either side and tilted in towards the centre. This provides better lighting along the sides of the reef for viewing and keeps the light spread off the viewing panes to reduce algae growth there. Running down the centre are nine Orphek Nilus units. These are the next generation of Orphek lights after the PR-156s. They add red and IR LEDs to the mix and are dimmable. We have measured 1100 PAR at the surface and 200 PAR at the bottom with these lights. The next version of the Nilus will have six rows of LEDs instead of four and we will upgrade to those when they become available for even better lighting coverage of the tank.

The current lighting scheme is as follows:

  • first hour – 10% blue
  • second hour – 100% blue
  • third hour – 100% blue + 10% white
  • next eight hours – full lights
  • twelfth hour – 100% blue + 10% white
  • thirteenth hour – 100% blue
  • fourteenth hour – 10% blue

Peter’s favourite combination is the 100% blue + 10% white as he says this is when actinic colouration in the corals really pops out. The PR-156s on the outside are set to 100% blue. The Nilus in the centre are set to 100% blue + 10% white.

Lighting history

We previously used AquaMedic metal halide/T5 combinations and still recommend these units. They are quiet, not too power-hungry and do not get too hot for this type of lighting. We tried 400W metal halides and found them to be too hot and too bright for a 30″ depth tank. The 250W metal halides were better but still too yellow. We tried plasma lamps but found they ran too hot, the fixtures to be big and bulky and difficult to work with, and the colour was far too yellow overall to be useful in a reef situation. The plasma lamps have since been redeployed to light the mangroves, an application in which the plasmas excel.  Several types of LED lamps were tested before settling on the Orpheks as best of breed.



Display Tank Lights Exposed


Fish Room

The Fish Room houses all pumps, water filtration equipment and fresh water filtration and storage. It also includes three MARS bays and a Hospital Tank. A window from the front viewing area of the Display Tank allows visitors to see into the Fish Room to appreciate how much goes on behind the scenes to keep the Display Tank looking its best. The walls and floor of the Fish Room are of marble, which acts like a giant heat sink and helps stabilize temperatures.

The temperature in the Fish Room tends towards the high side due to the Display Tank being directly vented into the room. At some point this will need to be ducted directly into the HVAC. A dedicated 2-part air conditioner currently works to counter the tank fan’s output in the Fish Room.

Floor sensors in the Fish Room detect flooding and will turn off all water to the entire house until the cause is cleared. Mr.Wilson has inadvertently tested this feature and confirms that it works well.


Display Tank Water Flow

The total flow in the display tank is approximately 10X total volume. There is no detectible detritus on the substrate at this rate.

Each end of the tank has an overflow. Each overflow is equipped with a 2″ Durso and a 1.5″ siphon. These are set up so that the Durso acts as a Herbie-type back-up to the siphon, with the Durso mounted slightly higher so that the siphon is always submerged and runs silently. The Durso handles 10% of drainage and the siphon the remaining 90% at each end. A separate pipe from each drain feeds directly to the Sump (four total).

(insert Mr.Wilson graphic of Durso/siphon here)

It had been planned to put a deep sand bed (DSB) in the overflows but this idea was abandoned because a). there is insufficient nutrient load to warrant another filter at this time, and b). access to the tops of the overflows is extremely limited, making any possible maintenance of a DSB extremely difficult.

There are two Closed Loops. Each Closed Loop is fed by two large strainers that are easily unscrewed for removal and cleaning. They have been intentionally left visible in the tank so it is easy to see if they become blocked in any way.

Closed Loop Strainers

Closed Loop Strainers

Each CL is equipped with two Abyzz 420 pumps. Each return has a penductor mounted to provide more flow using less energy.

The Abyzz pumps run at 65% (using only 94w) with 5-10 second surges at 80% every two minutes. At night the pumps slow down to 40/60%, so the controller certainly pays for itself. All the pumps run independently of each other, but are under the control of the Abyzz controller.

On the first Closed Loop, pump 1 sends water to two returns at each end of the L, piped over the top and down to the bottom. Pump 2 feeds a bottom drilled return half-way down the long side of the L and pointed towards the overflow.

On the second Closed Loop, pump 3 feeds two bottom outputs at the crux of the L, shaped in an H somewhat like a ship’s anchor and pointed in both directions. Pump 4 feeds two bottom returns on the long side pointed towards the overflow.

Return from the Sump is powered by an Abyzz pump. The returns come into the Display Tank from the top, aimed horizontally, and are knowingly left visible. There are two returns at the crux of the L plus a third half way down the long side. All returns are equipped with eductors and are aimed at the overflows to ensure surface perturbation for adequate surface skimming.

All the plumbing returns in the tank are covered with BASF Emaco S88ci marine cement to help blend it in visually with the live rock. It is now covered with coralline algae and we have even added a few small frags to help them blend in further.

Insert image from Mr.Wilson here

Water Flow Design – Side

Insert image from Mr.Wilson here

Water Flow Design – Top



Flow through the 250 gallon Sump is 1500 gallons/hour. This matches the flow required by the Skimmer. The four pipes from the Display Tank arrive at a shelf and drain through four 100 micron filter socks. The shelf is designed so that if any one sock becomes blocked the water can still drain through the other socks. If all socks are plugged the shelf will safely overflow into the Sump. These socks are replaced and cleaned three times per week.

The water then moves from the socks under a baffle into 200 lbs. of live rock in the main part of the Sump.

The Sump is equipped with two optical sensors and a mechanical float valve for Automated Top Off with fresh RO/DI water to counter evaporation.

There is an emergency overflow drain located high on the sump and plumbed directly to the floor drain to prevent overflowing.

A Poseidon Blue Line T3 Titanium pump sends water from the Sump through two Media Reactors, a Probe Holder, the Calcium Reactor and then onward to the Mangrove planters.

A refurbished Red Dragon II pump sends 1500 gallons/hour from the Sump to the Skimmer using 75 watts. The Red Dragon II has had many problems and has been pulled from production. This particular unit has had all new internal parts installed and is currently under evaluation. It is planned to replace this with an Abyzz pump similar to those used for the Closed Loops and Display Tank return as it would allow us to implement the automated flush cycle on the Skimmer and be scheduled by the Controller.

Water is returned from the Sump to the Display Tank via another Abyzz pump running at 100%. This routes through an empty Pentair reactor that was part of the original build but no longer used, then through an Aqua Logic chiller, two Aqua UV 40 watt ultraviolet sterilizers and finally back to the Display Tank. It is planned to remove the chiller completely as experience shows they are not required.

The Sump has a titanium grounding probe installed. The Sump location was chosen for safety, as it is an area where work on the tank is always being performed and there are a lot of electrical connections located close by. There is a second grounding probe in the Refugium.


Main Sump Schematic

Main Sump Schematic


Media Reactors

We are currently using the large size of Skimz media reactors but don’t like them.

First Media Reactor – holds Granular Activated Carbon (GAC). We are currently using Seachem but prefer ROX. However, ROX is difficult to source here on a regular basis.

Second Media Reactor – holds Granular Ferrous Oxide (GFO). We are currently using D-D ROWAphos.

Third Media Reactor – holds NP Biopellets. Since the tank’s nitrate (NO3) level is only 3 ppm this reactor has been disconnected. There is no need for an additional carbon source at this time. This reactor can be reconnected at a later date if the need arises.



The Probe Holder holds probes for the following: ORP, pH, water temperature, and conductivity  for the Display Tank, plus pH in the Calcium Reactor. A separate Probe Holder has a probe for Dissolved Oxygen (DO) in the Display Tank. All the probes are monitored by the Profilux controller. They require constant recalibration to the point that we do not allow the Profilux unit to fully control anything by the probes’ readings, but for monitoring purposes only.


Calcium Reactor

A Schuran Jetstream II unit is used for calcium supplementation. The Profilux controller operates the reactor via Aqua Medic solenoid and regulator. CO2 is provided by two twenty pound stainless steel tanks via CGA-320 connector. A pH probe in the reactor monitors the effluent via Profilux controller.

The Calcium Reactor effluent drips through the air into the top bed of the left-hand Mangrove planter. This allows for any excess CO2 to exhaust into the Fish Room safely and is good for the Mangroves. The drip method also aids in setting the feed rate of calcium to the tank.


Protein Skimmer

The skimmer is an RK25PE. The pump on the water input side was upgraded and is fed from the Sump by a refurbished Red Dragon II that allows us to use the Autoclean function to flush the Skimmer head as well as to turn down the skimming rate at night. The pump on the air input side was upgraded to a pressure rated Blueline 70HD pump (39′ head) that moves up to 1750 gallons/hour. This runs the stock Mazzi 1.5″ injector.

The RK25PE comes with a stock Autoclean sprinkler feature for washing down the head and collection cup. A Hayward actuator valve automates internal neck wash-down. The collection cup also has a wash-down feature. The Profilix controller operates a solenoid that runs wash-down eight times per day for one minute. Tap water is used to flush the head section out to the floor drain.

Ozone to the Skimmer is supplied by a Clearwater CD10/AD – 1250 mg/hr. This has its own built-in air dryer and heater and provides 15 standard cubic feet per minute (SCFM) of air recirculation through the Mazzi injector on the Skimmer so that it is sending a mix of air and ozone. The ozone system is operated by the Profilux controller via solenoid.

Hospital Tank



The Skimmer drains through three 100 micron filter socks into the 50 gallon Refugium. The Refugium is made of acrylic by ATM. It was poorly designed with no top bracing and had started to bow out on all sides. A support frame was made of 80/20 modular framing to support and maintain the top.

The Refugium sits atop the chiller. Experience has shown that no chillers are required for this installation and it is planned to remove it soon.

From the Skimmer’s filter socks the water flows through a set of baffles into the main area of the Refugium where we have a Remote Deep Sand Bed (RDSB) 4″ deep. The substrate is a finer grade (SeaFloor) than used in the Display Tank. We are not currently running a separate Cryptic Zone in the Refugium.

The area above the RDSB is filled with a large ball of Chaetomorpha algae which is harvested weekly for nutrient export. The Chaetomorpha is presently lit with a Stray Light 100 watt hanging plasma pendant. This unit is currently under evaluation as its 140° lens is too wide for this application.

There is no surface skimming in the Refugium so that a fine layer of microbubbles from the Skimmer forms over the Chaetomorpha section, encouraging a layer of scum to form there, reducing light penetration to the algae. This scum is removed manually several times per week.

The water next moves through a second set of baffles to a drain section which houses the water heater. The heater is an Aquamedic 1000 watt heater/controller connected to the Profilux controller. The water is maintained at 27°C with a 1°C swing.

There is an original surface level drain from the heater section of the Refugium that drains to the Sump. This drain was not capable of feeding the Display Tank’s return pump at the rate required so a second drain was installed below it to act as a siphon back to the Sump.

The Refugium has a titanium grounding probe installed. The Sump location was chosen for safety, as it is an area where work on the tank is always being performed and there are a lot of electrical connections located close by. There is a second grounding probe in the Sump.




The Controller is a Profilux 3 Elite plus expansion unit connected to 3 x 6-outlet power bars (PAB) which are all maxed at present.

The Controller monitors the following probes: ORP, Display Tank pH, Calcium Reactor pH, Temperature, Disolved Oxygen (DO), two optical sensors for high/low water levels in the Sump, plus Fish Room humidity and temperature.

The Controller controls the following processes: lighting for the Display Tank, Mangroves and Refugium, Automated Top Off to the Display Tank, the MARS bars and the Hospital Tank, the Calcium Reactor, the fogger (misting) system for the Mangroves, and the Skimmer wash-down feature.

Abyzz Pumps

We are currently using Abyzz 420 magnetic drive, Direct Current, brushless pumps. These are absolutely silent, create no perceptible heat and run extremely efficiently at much lower energy requirements than most other pumps. The Abyzz 420 is capable of producing over 6400 gallons/hour at 0′ head using only 400 watts when run at 100%. The Abyzz pumps have separate wall-mounted power controllers, and this is where the heat is generated, well away from the water. This type of pump is what is known as a Variable Frequency Device (VFD) and is far more efficient than direct drive AC pumps. There is a total 500 Watt draw when all five Abyzz pumps are running concurrently.

The master ACS controller is capable of controlling up to eight pumps, giving us options for surge, pulse and wave features. When run at 50%, the Abyzz pumps only use 110 watts. The ACS monitors/controls rpm, pump temperature, water temperature at pump, power consumption, 4 day speed cycles from 0-100% in one second or one minute intervals, 4 night cycles, audible alarm, thermal and run dry on/off. They are absolutely silent, 6,400 gph, 9m head pressure, titanium shaft and starter. The wet end of the pump runs at about 85˚F, compared to most at 130˚F.

We currently use the ACS controller to run the pumps for variable lengths of time in long intervals and short intervals. The long interval can be 90-240 seconds, with pressure varying from 50-60%. The sort interval is 10 seconds and pressure varies from 75-85%.

A photosensor in the Refugium tells the ACS controller when it is night. The ACS controller then reduces pressure to vary between 35-55%.


Automated Top Off

The Automated Top Off system replaces water lost by evaporation. It is controlled by the Profilux controller via a solenoid switch sourced from AutoTopOff.com. Fresh RO/DI water is moved through a pressure line under nothing more than city mains pressure to the Sump when notified by the Sump’s low water level optical sensor. A timer on the Controller only allows freshwater top off to run for one minute every five minutes so that no large, unexpected changes to salinity can occur. As well, any large changes detected by the Display Tank’s temperature probe can also indicate too much fresh water being added and the Profilux controller will stop Automated Top Off.

The Sump is equipped with an optical sensor for low water level which the Profilux controller uses to turn on Automated Top Off with RO/DI water. A high volume mechanical float switch shuts off Automated Top Off. A second optical sensor sets off an alarm for high water level if the mechanical float switch fails. This was supposed to be controlled by the Profilux but only the alarm works. Higher than any sensor in the Sump is a 1″ hose leading to the floor drain in case all sensors should fail. If the floor drain should fail and start to flood the Fish Room a Water Bug floor alarm will shut off all water pressure to the entire house until the drain is fixed.

(insert graphic from Mr.Wilson here)


Water Changes

The RO/DI unit moves water using nothing more than city mains pressure to the first reservoir tank. The water in this tank is kept aerated with a Poseidon T3 Titanium pump. Water from reservoir tank #1 flows to reservoir tank #2 by gravity. Tank #2 is where salt is mixed using a second Poseidon T3 Titanium pump.

Water changes are done manually at present. A valve is opened at Tank #2 and the same Poseidon T3 pump used for mixing salt is re-used to send fresh saltwater to the Sump. Waste water is drained directly from a hose bib on the pipe of the Abyzz pump that serves the Display Tank off to the floor drain.

Currently we are changing 100 gallons per week.

(insert graphic from Mr.Wilson here)


RO/DI Water Filtration

There is a water softener and carbon filter on all water entering the home. For the RO/DI filtration system, tap water is fed into a mixer that preheats the water to 77°F. This goes through a resettable counter that counts gallons and lets us monitor water volume used so we know when to change the Reverse Osmosis (RO) membranes and filters. Our current water pressure from the utility is 80 psi which is well sufficient to run our water filtration without an extra pump.

We are using 3/8″ tubing to connect from the supply to three Watts 20″ transparent canisters: the first holds a 5 micron sediment filter cartridge, followed by GAC cartridge filters in the next two canisters. The GAC is doubled due to Ontario water’s high iron content which renders block carbon filters useless.

After the canisters we split to two parallel 1/4″ lines that each go through an auto shutoff valve that works by back pressure to control flow until needed.

Next step is to go through two parallel Watts reverse osmosis (RO) membrane units rated for 150 gpd each, which give us about 125 gpd at current pressure. These are followed by flow restrictors and check valves that provide the back pressure needed by the membranes to perform properly. The parallel lines are then rejoined into one to go into the Deionization Filter (DI) canister.

The Watts Full Flow Big Blue 4.5″ x 20″ canister holds a Deionizing (DI) cartridge with 2,350 grain capacity. This should give us 12,000-13,000 gallons of filtration before it needs changing.

Sensors for Total Dissolved Solids (TDS) are located before and after the DI canister. These are connected to a HM Digitial PS 202 Conductivity monitor that uses an Asco Red-Hat II three-way solenoid valve to ensure that only water with a preset TDS level of 10 ppm or less is allowed to go from the RO membranes to the DI canister, thus increasing the life of the DI cartridge. Otherwise, water with higher TDS is redirected by the three-way valve to the waste line.

The TDS level from the tap, and by extension the RO membranes, can creep up from season to season but will gradually lessen as the water is allowed to run clear. This system ensures we do not introduce temporary high TDS levels into the DI cartridge. The current set-up is giving us a 1:1 ratio of waste to product water.

G = Grains capacity
X = Grains of hardness
Y = Gallon Usage

X = T/17.1 and Y = G / X

X = T / 17.1
X = 3 / 17.1
X = 0.1754

G = Y / X
G = 2350 / 0.1754
G = 13,398 gallons of product water projected

The following lines feed off the RO/DI filtration system:

– 1 line to the freshwater reservoir for Automated Top Off and to supply the saltwater reservoir for Water Changes
– 1 line to each of the three MARS bays for evaporation top off
– 1 line to the pressurized tank that supplies the fogger for misting the Mangroves
– 1 line to the pressurized tank under the sink to an extra tap for rinsing with RO/DI water as required
– 1 line for evaporation top off to the Hospital Tank

RO/DI Water Filtration

Freshwater Filtration Schematic

Freshwater Filtration Schematic



Two sets of planters on two adjacent walls have mangroves planted approximately every six inches. The mangroves are rooted in Miracle Mud™. Water from the Sump is fed into the top levels and allowed to cascade down from one level to the next.

Eight times per day, the Profilux controller, via a solenoid, turns on a fogger which draws RO/DI water from a reserved pressurized container (100 psi) to mist the mangroves for one minute.

The mangroves are lit by two StrayLight 290 Watt plasma lamps. We found the plasma lamps too yellow for use over the Display Tank but excellent for lighting the mangroves.


Mangrove Refugium Set-up

Mangrove Refugium Set-up




MARS = Marineland Retailer System

Now you know. This question has been asked repeatedly on the RC thread. They have jokingly been called “MARS bars” after the candy bar. The original MARS were designed for freshwater fish to be sold in pet shops and department stores. Mr.Wilson had to totally replumb these to be useful in the Fish Room, prompting the alternate nickname of “Wilson bars”.

Three bays were purchased to act as quarantine tanks for new arrivals, to act as a holding area for any fish or invertebrates from the Display Tank that aren’t doing well, and then to hold other lifeforms that may not be suitable for the Display Tank. Each MARS bar holds 150 gallons of water.

The refurbishment included:

– replacing the lighting with LEDs
– replacing the sump
– replacing the pump with an Iwaki pressure rated pump
– adding nozzles on return lines to increase flow
– adding a UV sterilizer
– adding lines from the main Fish Room calcium reactor
– adding filter socks
– removing the chiller
– adding an ozone generator controlled by the Profilux
– adding a silencer to the ozone generator’s air dryer

A Skimz reactor is used for calcium. Skimz brand skimmers were tested but proved disappointing. We are currently waiting on replacement units for evaluation.

MARS 1 – This is currently the quarantine set-up. It is used for high levels of medication. To this end, a non-calcium substrate is planned. It is kept at reduced salinity as this is how newly arrived fish are usually shipped. Since these tanks are for treatment, an Iwaki 55 is used for slower water movement. No skimmer will be used as it would take medication out of the water. An Aqua Medic 55 watt UV sterilizer is used. LocLine sprayers were added to improve flow from the return lines, but only to a restricted extent.

MARS 2 – This bay is intended for exhibiting fish and inverts and providing extra care for Display Tank inhabitants from time to time. Low levels of medication (Praziquantel) are used in this bay. There is no skimmer at this time. The pump is an Iwaki 55. An Aqua Medic 55 watt UV has been added. Water return lines are equipped with eductors for a three times increase in water flow. An aragonite substrate similar to the Display Tank is used.

MARS 3 – This bay is intended for exhibiting fish and inverts. No medication is used. There is no skimmer at this time. The pump is an Iwaki 70, pressure rated at 1700 gph. An Aqua UV 40 watt UV unit has been added. Water return lines are equipped with eductors for a three times increase in water flow. An aragonite substrate similar to the Display Tank is used.


Automated Feeders


For the time being we have an ongoing quest to come up with a solution. We have not found any sort of commercial unit that can handle the thawing, rinsing and dosing of frozen reef foods. We are working on finding a custom solution.

We are, however using an Eheim feeder over the Sump to serve dry foods for the invertebrates. The Eheim pump delivers powdered coral foods sized in the 0-150 micron range four times a day.


Hospital Tank


The 130 gallon Hospital Tank (30″L x 30″W x 32″H) was added to treat larger fish such as tangs and angels; fish that can’t be comfortably housed in the MARS tanks. It may also be used for treating larger inverts from the main display.

As the stocking process for the Display Tank matures, the Hospital Tank may possibly be converted to house a collection of azooxanthellate invertebrates, but that is for the future.

The Hospital Tank has no substrate and uses a biofilter at this time.

Hospital Tank


Backup Generators

Two Generac 17KW natural gas-powered generators from Home Depot provide backup in case of power failure. The power to the house was upgraded from 200 amps to 400 amps. A separate 60 amp panel for the aquaria came with the generators. There is a maximum 45 seconds delay before the generators kick in. They are tested once per week, at both low and high speed.

Backup Generator


Culture/Feeder Set-up – Proposed

Culture/Feeder Set-up

Culture/Feeder Set-up