180g Mixed Reef Aquarium

180g Mixed Reef Aquarium
180g Mixed Reef Aquarium

Ok the wait is finally over. I managed to get my new 180g 6ft tank which is a tank dedicated to the beautiful Clown Triggerfish I recently purchased. But first a bit of history...

You may wonder why have I purchased this fish if I did not have a tank prepared for it? The idea was that it would go in to the 480g tank. But that idea was terribly flawed. The fish lasted 12 hours before I had to remove him. He terrorized my urchins, green brittle star, Naso tang, Comet and who knows what else. This is just not a community tank fish.

So obviously I could have taken him back, but that was not an option as I really started to like his intelligence and unusual behaviour. That is how the 180g tank was born...


The tank is a custom built glass tank made from 10mm side panels, a double layer 10mm base and cross bracing for structural support. It rests on a polystyrene cushion on a metal stand, which is covered in wood for a nice dark cherry finish. The top has a closed lid. The idea was to have 3 sides visible. Currently it is standing against a wall separating the kitchen and the living room, but we are going to break down this wall eventually - hence no background in the shot above.

The tank measures 1.8m long, 0.6m wide and 0.65m high for a total water volume of roughly 680L or 180g of water. The stand is extra high and provide easy access to my filtration equipment located underneath the tank.

Beneath the tank is a custom sump, measuring 1m long by 0.4m wide by 0.55m high. The sump holds all the equipment. I have no refugium in there as the DSB is supposed to work well enough. The water is returned from the tank via a overflow with a Durso standpipe, splitting between the skimmer and the sump with a ball valve to control the ratio. From there it flows over a simple glass over/under diversion to limit mini bubbles. A powerful Eheim return pump returns the water through a chiller to the tank.


I have reused my old dual T5 fittings from my 145g tank since this tank does not need intense lighting. So in total I have 4 x T5 54W tubes, three of which are Aquablue+ and one Actinic. The Actinic and Aquablue+ light is on a timer and come on at 09:00 and is turned off at 20:00. The other two Aqueblue+ lights come on at 10:00 and is turned off at 19:00.

Mechanical Filtration

The main mechanical filter is the sump, where detritus settles.

Chemical Filtration

Currently I only use Rowaphos in a small Two Little Fishies reactor for removing phosphates. I will eventually add a small GAC reactor. Since the Clown Trigger is a very messy eater, I have a huge Deltec AP851 skimmer in the sump, rated at 280g. This skimmer is the main preventative filtration device and my main hope of maintaining good water quality.

Biological Filtration

All the biological filtration is handled by the live rock and DSB (Deep Sand Bed) in the main display. I have about 60kg of mixed live rock - Kenyan, Indonesian, Tonga and a couple of others. All the LR was properly cured before I introduced it to the aquarium, since I was out of time. The DSB was quite a mission to get right. After a huge search I managed to find a shop close by (well, 60km away from my house) that sells Caribsea oolite Sugar Sized Aragonite. I purchased 14 bags, 11 which were oolitic, 2 were Bahama aragonite and sea shells, and 1 was live sand (to seed the sand bed with). After washing the sand (try washing oolitic sand - it is quite frustrating) - obviously not the live sand - I managed to get a 13cm (5") deep sand bed. The interesting thing is that within 2 days of adding the LR and DSB, I saw worms in the sand bed making their tunnels. This took 1 month in my 480g tank where I used a much coarser sand. It is therefore my opinion that a DSB only really functions properly when using oolitic fine sand.


I thought since this tank does not have a lot of equipment, I would not need to bother with a chiller. Boy was I wrong. The temperature would go up to 28C during the hot summer days we recently experienced in South Africa. So I copied my usual setup. I have two 300W Jager heaters for heating and a Haelia HC500 chiller for the cooling. Works like a charm.


Currently I have no automatic addition of additives - however I am strongly considering a Tunze Kalkwasser dispenser since the wastes will drastically impact on the Alkalinity. I do have a Tunze osmolator which provides the RO topup water from a custom RO tank.

Return Pump

Since this tank has an open back, I really needed to have the most quiet pump on the market - and the one that worked for me was the Eheim 1264 pump. This is a powerful 4500l/h pump that is so quiet one can barely hear it with your ear pushed against the pump. It is very, very expensive but worth it.


Even though this is not a SPS tank, it is still important to have good enough flow so that detritus do not settle on the bottom. The powerful return pump together with a Tunze Stream 6101 pump I have approximately 9500l/h flow, which is about 14 times turnover. I can increase the flow from the Tunze, but then the sand starts blowing away. For now it seems to be good enough.


I have purchased an extra Aquatronica plugbar for controlling the heater and chiller. The plugbar also powers the light and handles the timer feature. I only have a temperature sensor since I came to believe that the density and pH probes are not really useful. Firstly, they are both extremely expensive. Secondly, they need monthly calibration otherwise even though they seem to provide a sane measurement, they are in fact drifting and wrong by as much as 0.2 units for the pH and about 0.003 for the density. Furthermore, I saw that sometimes my density probe would suddenly jump to an insane value such as 1.048 for a couple of hours then drop back down. What good is this for alerting if the probes fluctuate?

The lights are on timers, and RO water is automatically added.

Water Parameters

Measured: 16 Nov 2007

pH8.10 - 8.30
Temperature25.4 C - 26.5 C
Specific Gravity1.0250
Ammonia - NH30 mg/L
Nitrite - NO2-0.02 mg/L
Nitrate - NO3-5 mg/L
Calcium - Ca
Alkalinity7 dKH
Phosphate - P0.045 mg/L
Magnesium - Mg


I feed my Clown Trigger daily, and it varies from closed Mozambique Clams, mussels, crab meat, prawns, scallops to the occasional lancefish or squid. The wrasses and grouper in the tank eat the particles the Clown Trigger spits out - hence they act as my clean up crew.


Daily tasks are feeding, checking RO bucket and just general inspection that everything is still fine. Once a wee I'll clean the glass, fill the RO reservoir if necessary and clean the skimmer cup. Once in 6 months I'll change the Rowaphos. I'll then also do the usual equipment cleaning procedure.


I am tagging on my existing UPS for providing backup for all the equipment bar the lights, chiller and heaters. This allows me not to worry about power outages.

PS: Equipment pictures will follow soon. I have just not yet had any time to take the pictures.