Building a Reef Aquarium Part 5

Fish fish fish! Yes the time has finally come to start adding the fish stock to the aquarium and empty my bank account of all my hard earned money! Who needs a new flat screen TV when you can have a stunning shoal of Anthias swimming around your aquarium? But first what’s been happening in the tank? Well it’s all good really, the corals have been thriving and growing well, most of the frags that I put in there having already doubled, trebled or even quadrupled their size in the last few months. As you may remember the tank has almost totally been stocked with coral frags taken from my farming facility but I did have a few empty spaces left for some other corals and a couple of trips to STM in Sevenoaks turned up a some coral peaches. I purchased a lovely red Goniopora along with three different species of Acropora all of which have settled in very nicely and started to grow. I still have one or two spots left empty which I will save for any other corals that take my fancy on my travels.

All of the equipment on the tank is performing well, and there really is little maintenance that I am having to do. I have started performing water changes on the system, consisting of 20% each month and the water parameters are stable as follows:

Salinity 33ppt Temperature: 26-27C Ammonia: 0.0ppm Nitrite: 0.0ppm Nitrate: 0.0ppm Phosphate: 0.00ppm Magnesium: 1300ppm

The magnesium has dropped a little from the readings of 1440ppm a couple of months ago but as yet I have not had to start supplementing this element. You may also recall that this system has a large section of bioballs in the first section of the sump, designed to improve gas exchange and prevent micro-bubbles from entering other sections of the sump or get pumped back up into the main tank. These bioballs would also work as a biological filter and there has been a lot of talk in the past that these kinds of set-ups can act as a ‘nitrate factory’ but provided your system is well balanced this is simply not the case. Problems of excess nitrates only come in systems that either have too high a bio load or not enough filtration to deal with any nitrates produced, this system has neither and the ‘dry’ bioballs in the sump have not, nor will they ever cause nitrate problems in this system so long as the rest of the system is maintained properly.
So on to the fish stocking, the tank already had a Yellow Tang and a Unicorn Tang in there to act as initial grazers and they have been performing their jobs well and are fit and healthy. Usually you will only stock a system with a couple of fish each week but I wanted to have a decent selection of fish to choose from and I knew that I could push the boundaries a little so I went up to the wholesalers TMC to pick the first batch of fish to add. Boy was I like a kid in a sweet shop! Hundreds of tanks at TMC filled with thousands of fish and I had my credit card!
When it comes to selecting fish for a reef tank you do have to be careful as there are many species of fish that are not suitable to keep with corals, often because they would naturally feed on them. There are also many species of fish that should not be kept together as the aggression between the species is too great. As a rule you will generally find that species of fish that occupy different niches will generally get on, grazers are less likely to be aggressive to planktivours than they are other grazers. Bottom dwelling species are less likely to be aggressive to open water species than other bottom dwellers. A good book is essential if you are just learning which species of fish can be housed together and which species are considered reef safe and make sure you do your research before you buy.
Fish are also less likely to be aggressive to other fish if they are added to the aquarium at the same time, whereas once fish have been settled into an aquarium they can become quite territorial to other species that are added later. If you are looking to add several species of fish that occupy the same niche, for example several different species of Tang or Surgeon then you are best off adding these at the same time so that they can establish their own territories together but be careful not to add too many at once as the biological filtration needs time to adjust to the increased bio load.
I wanted a selection of fish in the tank that would occupy different areas and exhibit a range of behavioural characteristics.  I started off with the bottom dwellers and as they are one of may favourite species of fish I chose a pair of Mandarin gobies (Synchiropus splendidus). These are a fantastic little fish that are very well suited for reef aquariums, however their only drawback is that they generally will only feed on live copepods and isopods in the aquarium and will rarely take dead food offered. Because of this you should make sure that if you decide to keep these fish your aquarium has an ample population of suitable food for them. You can also supplement their food if you do not think there is enough present in the aquarium by regularly adding live copepods that you can buy or culture yourself.
Another point to remember about these fish is that you can only keep male and female pairs together, never try to put two males in the same aquarium as they will fight to the death. Mandarinfish are easy to sex as the males have greatly elongated first rays to the dorsal fin. The male and female that I bought have been in the aquarium now for over two months, they are both healthy with fat stomachs from feeding on the ample supply of live copepods that are in the tank.
Over the last few days I have noticed that the female is heavily gravid and I am expecting to see courtship behaviour and spawning within the next week.
The next bottom dweller that I chose was another one of my favourite fish, Randall’s shrimp goby (Amblyeleotris randalli). These cave or burrow dwelling fish have a white body with thick orange stripes and an impressive sail-like dorsal fin and black eye-spot on the males. They are quite a secretive fish but generally very hardy, I have another one in a different system that I have had for nearly eight years. The one I purchased for this tank is just a juvenile at around 4cm in length and still very shy.

I then chose a couple of active grazing fish to go with the two Tangs that were in the system and settled on a Regal Tang (Paracanthurus hepatus) and a Potters Angel (Centropyge potteri). As with all dwarf Angelfish there is always the risk that they will peck at various species of coral, some individuals are very well behaved in this respect, others are not, mine fell somewhere in the middle. There are a couple of species of small polyped stony corals that he has pecked at the polyps on, namely the pink Pocillopora damicornis and the pink Stylophora pistillata (I guess pink is his favourite colour) but he has not caused any significant damage.
These fish are found around the Hawaiian islands and are often considered difficult to acclimate to life in aquaria but fortunately this has certainly not been the case with my individual as he settled in immediately and was feeding after only being in the tank for a few minutes.


I then wanted some species to occupy the more open water areas of the tank and decided on the two species of Firefish, (Nemateleotris magnifica) and the Purple Firefish (Nemateleotris decora). Again these fish are very well suited to reef aquaria, they are easy to keep, readily excepting most foods offered and are generally very peaceful. I also choose several Pseudoanthias lori and a Splitfin Anthias (Luzonichthys spp) to occupy these more open water areas of the tank along with the Firefish. Anthias are generally a little more demanding in their requirements than some other species of fish that you can choose. Naturally Anthias spend much of their day feeding on very small items of plankton drifting in the current and as such they need regular feeding in aquaria to prevent them from becoming malnourished. If you decide to keep Anthias then I would recommend at least three feeds per day of appropriately sized zooplankton to keep them healthy.
During my tour of the tanks at TMC I came across a little gem tucked away in a small tank – the Canary Deep Water Damsel (Chrysiptera galba) which is found around the Cook Islands. Although this fish is quite common in it’s natural habitat it is only rarely seen in the aquarium trade as it is not so easy to collect from the wild due to it inhabiting depths of around 150 ft. This also makes it rather expensive, my individual would have had a retail price of around £35.00 which is not particularly cheap for a Damsel but it is certainly worth the price! This fish is bright yellow in colour with long flowing fins with an electric blue trim on the dorsal and ventral fins and two blue stripes through the eye. This is a very mild mannered Damselfish that does not grow particularly large and settles very quickly into aquarium life, he quickly became one of my favourite fish in the tank.
Finally I chose two species of fairy wrasse on this initial trip, Cirrhilabrus filamentosus and Cirrhilabrus adornatus both of these generally make good reef aquarium additions although the Whip-fin fairy wrasse (C. filamentosus) has been misbehaving a little by occasionally pecking at the polyps of the Stylophora pistillata but again not to any level significant enough to cause any real problems. I have to confess to making a rather school boy error on the stocking of this tank with fish.
After the initial stocking from TMC I decided I wanted a butterfly fish simply because I really like them. Now Butterfly fish are a bit of a grey area when it comes to compatibility in reef aquariums, some species are suitable for stocking with corals, others are obligate coral feeders and should never be added, while other species are somewhere in the middle. During a trip to a retail shop I was seduced by a rather spectacular Double Saddleback Butterfly (Chaetodon ulietensis) which is omnivorous and if I was lucky would not pose too much of a threat to my corals. What a mistake to make! No sooner had this fish been added to the tank he merrily started munching on pretty much every species of SPS coral that I had in the tank. I then spent two weeks trying to catch him again to remove him. Now catching a fish out of a reef system is no mean feat, but finally after two weeks of feeding the fish out of a net with brine shrimp in it I managed to entice him close enough to the net to scoop him up and transfer him to a system containing only soft corals which he did not find quite so appetising. I won’t be making that mistake again! Fortunately there was no lasting damage to the corals and once he had been removed the polyp extension of the corals was back to normal.
There are many stunning and beautiful fish that you can add safely to your reef aquarium but it is important that you choose them carefully and make sure that you research each species you are considering first. Many species of fish have particular dietary or habitat requirements so ensure that you and your system are going to be able to provide for them the environment that they need. Careful research before selecting your fish will lead to a harmonious and thriving community and always avoid those impulse buys that can lead to so much trouble! This system is now almost complete, there will be a few more fish and a couple more species of coral added in the future but for the most part the stocking is complete. We will revisit this tank in several months time to see how things have developed.