Building A Zero Impact Marine Aquarium
Part 3
My Garf Zero Impact Aquarium is now fast approaching the ripe old age of one year. It has been an interesting twelve months during which time the tank has given a lot of pleasure as well as presenting the occasional challenge. In this update I will look at the problems I have faced with algae and high summer temperatures, the propagation of corals as well as detailing any changes I have made since last time.
Propagation
You can see how I position a rock so it touches the stalk of Xenia. This stimulates it to grow across. Once halfway over, the stalk is cut leaving a stump that very quickly grows a new head. An example of this is the little Xenia on the left. In this photo you can also see a Sinularia cutting being held onto a rock with an elastic band.
As time has gone by and the corals I introduced as cuttings have grown I have begun to try my hand at propagating. My first attempts have been with the species that have grown the most in the tank.
I have used two different approaches with Yellow Polyps. The simplest is to place a rock so that it touches some of the polyps in the colony. As the colony grows, it will spread onto the rock which can later be moved to a new location. The other method is to use a scalpel blade and simply cut a polyp from the rock. The base is then dried off with a bit of kitchen towel and super glue gel is used to glue it to its new location.
The method I have used to propagate Clavularia is to cut out a small section of the purple encrusting mat from its rock and simply super glue it to where I want it.
Propagating Sinularia is simplicity itself. Using a pair of sharp scissors cut one of the fingers from the coral. Then use an elastic band to hold it onto a rock. Within a week it will have attached and the elastic band can come off.
Not only my favourite coral, but also my fastest growing. Propagation is simply a matter of placing a rock so it touches the stalk. This stimulates it to grow onto the rock. When the stalk has attached and moved halfway over, I cut it with a scalpel blade. The old head and stalk are now on the rock and can be relocated, while the remaining stump quickly regrows more pulsing polyps.Another photo showing a different Xenia being propagated using the same method. Again you can see a stump from a previous cutting regrowing another head. In the background you can see a circular cement plug onto which I have propagated some clavularia.
The Algae Wars
I am sure that Algae in one form or another have probably driven more people out of fishkeeping than anything else I can think of. There can be nothing more soul destroying than watching that beautiful aquascape you have constructed slowly get covered in a greenish brown turf. I for one battled with it during my freshwater plant tank days and now more recently have had to deal with it in my reef tank. Thankfully I seem to have the algae under control now and although there is still some in the tank, you have to look closely to find it. My algae wars were fought against Valonia (bubble algae), hair algae and most recently cyanobacteria.
Valonia
This began appearing in the tank quite early on, growing on the pieces of live rock that I had used to seed the tank. I had heard that Mithrax crabs would keep this in check, but try as I might, none of my LFS ever had any in. Eventually I resorted to picking the stuff off by hand using tweezers. At first this was very time consuming, but there was a lot to pick off. However, by picking off what I could every time I did a water change it become quite a quick process. At first I was very concerned that I might pop the bubbles and so spread the spores and create a plague, but then what would the Mithrax crab do? Certainly they don not eat the bubbles whole but rather keep them in check as they appear, much as I was doing. I have still got my eye out for a Mithrax crab but until such a time as I can get one, the tweezers will keep things under control.
Hair Algae
Early on in the life of the tank, I had a minor outbreak of hair algae. Fortunately it did not last long and was probably down to the tank being newly set up. However around the six-month mark it reappeared again. Strangely it only grew on the side of the rocks facing the back of the tank and as such did not spoil the look of the tank. Every few weeks I would manually pick off what I could and in this way I kept it in check. Initially this was fine, but gradually I noticed it beginning to spread and so decided it was time to take further action.
I began by checking the nitrate and phosphate levels in the tank. To my surprise, according to the test kits (Hagen), they both registered at 0 ppm. This did puzzle me, as with such low readings why was I having this algae problem. After running a few searches of discussion groups on the topic of hair algae (a popular subject!) I found a plausible explanation. Apparently, the algae is such a fast grower that it utilises the nutrients it requires very quickly and as a result the levels in the water are kept very low.
All very interesting but how would I stop it growing back? Answer: A Yellow Tang. I had noticed a lovely specimen in my LFS that they had for over a month. It had good colour, was nice and plump, feeding well and not a white spot in sight, but I still was not sure if I should add it. While researching this fish it became very clear that there was not a consensus of opinion on what the minimum tank size for it should be. I thought long and hard and sought out advice from those with experience of the fish. Eventually I decided to buy it. It has certainly done a grand job of clearing every last bit of hair algae, but I have to say, that even at 2 inches, I am still not convinced that a 55gal tank is big enough for this fish, I get a bit claustrophobic looking at it. It is a lively animal and because of this I personally feel it looks cramped in a tank of this size. If I had the choice again I would not have put the tang in.
Cynobacteria
My final battle was against cyanobacteria. This proved to be the most annoying of the three as it had the capability of spoiling the look of the tank in less than the space of a day. I had experienced a very minor cyano outbreak in the early days of the tank but just after I had conquered the hair algae, it reared its ugly head again. At first it covered localised patches of sand but this quickly spread to cover all the illuminated areas of the substrate. It then began appearing on the rocks and later even on some of the corals.
Clearly the root of the problem was a too high level of nutrients in the water probably caused by inadequate skimming and possibly too much feeding.
In order to improve water quality I began a regime of weekly 5 gal water changes (using RO water). This also gave me the opportunity to siphon out the sheets of cyano that had formed (it certainly is smelly stuff!). The annoying thing was that within a day it would be back. Between water changes I resorted to using a toothbrush to scoop up as much of the cyano as I could. I then looked to improve the skimming. As replacing the Seaclone was not an option I began to look at improving its performance. I did this by cutting down the central tube as detailed in the Seaclone modification article on this site. How much difference it actually made I am not sure but there were definitely more bubbles in the column.
Next I decided to stop adding Seachem Reef Plus and Reef Calcium as I figured the regular water changes would be doing their bit to maintain levels of trace elements. I also cut back on feeding primarily by stopping adding the Cryopreserved Phytoplankton. The final change I made was to my lighting. The tubes were now about 9 months old so I decided to replace them all. I had read that the spectrum of the tubes shifts as they age in favour of the wavelengths preferred by the cyanobacteria so I felt it was worth doing.
With all these changes I was hoping to see a rapid decline in the cyano but sadly not. It remained and I began to get more and more disheartened (almost to the point of giving up on the tank!). Fortunately, after over a month of water changing and cleaning I began to see minor improvements. The cyano did not appear to be coming back quite so quickly. Boosted by this, I continued with this approach until eventually the stuff stopped coming back. This period of time was a real test of perseverance and I would say to anyone trying to tackle the problem, stick with it, you will get the better of it eventually.
Hot Temperatures
Up until the first hot spell, the tanks temperature was around the 78F mark (give or take a few degrees). It did fluctuate during each 24-hour period (more than I would have liked), but then without the aid of a cooler I doubt if you could maintain a rock steady temperature. However, as summer approached and the air temperature began to climb, so did the upper temperature of my tank. Even though it never reached alarming heights, I needed to take some action. The first thing I did which made an immediate difference was leaving the hood lid partly raised all day. This prevented heat building up inside the hood and went a long way to solving my problem. However, on particularly hot days this was not enough. I then resorted to using a desk fan which when directed at the open lid proved very effective at further cooling the tank. It did mean I had to be vigilant of tank temperatures in order to decide when to put the fan on, but it saw me through the hot spells without any major problems.
Looking towards next summer I will need to redesign my lighting hood to incorporate some form of cooling. This will probably involve building in a couple of small cooling fans of the type used in PCs. By wiring them to a thermostat they will only come on when required. It should be noted that Reef Tank temperatures have been the subject of much discussion recently with much higher temperatures (84F) coming into favour. As a direct consequence of all this, I now follow a much simplified approach to the dosing of the tank. I add a daily scoop of Tropic Marin Bio Calcium in the morning and occasionally add a little Kent Superbuffer to my top off water. The tank gets a fortnightly 5-gal water change, which I believe helps to restore some trace elements, but apart from this, no other additions are made. I do of course monitor both calcium and alkalinity levels and these are doing well (Ca 400ppm and Alk 10 dKH)
Livestock
Following the last update, I experienced the first casualty in my tank, the Royal Gramma. When I bought it, it was one of the nicest specimens I had seen of this fish, but within the space of a week it just deteriorated and died. When this happened I was very concerned that it might have brought in something that might kill my Clowns, but thankfully no. I have since learned to be more patient and wait until the fish I am interested in has been in the dealers tanks for at least a week or two before buying. I followed this approach with the last two additions, a Yellow Tang and an Orchid Dottyback and both have done well and are looking great. On the invert side, the only new additions have been a Purple Frilly Gorgonian (Pseudopterogorgia bipinnata) and a Devils Hand Leather (Lobophytum pauciflorum) both of which came from a hobbyist who was selling up his reef tank.
A strange event did occur involving one of my pulsing Xenias. It had been looking a bit deflated for several days and I began to fear the worst. Then bit by bit it slowly returned to its former glory. In the week that followed I began to notice lots of single pulsing polyps all over the tank. Why or how this happened I still do not know, but many of these single polyps have now grown into miniature Xenia stalks which are now spread throughout the tank.
Conclusion
So, one year on and a lot has happened. That pile of grey cement and shells with the odd coral cutting here and there is now a great looking reef. There is easily more coraline than rock to be seen and thanks to my efforts at propagation, there is not a rock in the tank that does not a coral (or two or three or more!) growing on it. Water conditions are good and the rock is providing effective filtration (like real live rock). In fact nitrates have been undetectable using both my Interpret and Hagen test kits. Although it has not exactly been plain sailing all the way, the problems that I have encountered have been no different to what I might have had using natural live rock and corals. I started the project as a complete marine novice, yet by following the Garf Recipe I have enjoyed great success with my tank. It is an approach I am more than happy to recommend, especially to anyone wanting a reef tank who has a concern for the hobbys impact on natural reefs.