Building A Zero Impact Marine Aquarium
Part 5
On November 14th 2001 the Garf Tank was 2 years old. Since the last update very few changes have been made, simply because everything has been working very well. Additives, water changes and feeding routines remain as they were. There have been no significant alterations to the variety of livestock, although everything has grown in size. In fact the only big change (if you can call it that!) was the replacement of the Triton and Blue Moon tubes in favour of 3 Arcadia Marine Whites and a Blue. This has removed the slight pinkish cast that I always felt the Tritons gave to the light.
In this, the final update, I will look at how I have dealt with leaving the tank during holidays, with the propagation of Sarcophyton corals and a look at the often voiced misconceptions about cement rock reef tanks.
Coping With Holidays And Absence
Anyone who has built up and maintained a reef tank will know that leaving it for any period of time can lead to much anxiety. During the life of the Garf Tank there have been several occasions when it has had to be left unattended. The longest of these being a week. There is always a level of risk attached to doing this but not having anyone to tank sit while I am away, I do my best to minimise what risks there are.
These are some of the things I do:
- In the month prior to a holiday, I make a point of not changing anything in the tank including livestock, foods, additives or rearranging rocks or corals.I try to ensure that the tank is as stable as I can make it. Adding any new livestock is probably the most risky thing you can do before going away. If there is anytime that it is likely to die, then it has to be in its first weeks in a new tank. If this happens while you are away it will have a negative impact on water quality, which could in turn lead to the demise of other livestock, and so a domino effect begins.
- I ensure water quality is as near perfect as possible. This should be the goal of every reefkeeper anyway, but even more so if you are going away.
- I ensure fish and livestock are well fed. Providing you have a good feeding routine and do not have species that need several feeds daily e.g. Anthias, they should be able to cope with a short period of fasting and suffer no ill effects. I do not increase feeding before going away as this will have a negative effect on water quality, which I do not want. Instead I simply maintain my normal routine.
- I do not service my skimmer or powerheads too close to the time of going away. That way if there are any problems arising from the service they will have been picked up before I go away.
- I set up a system for topping off water lost through evaporation. I believe there are commercially available systems that do this, but with a little ingenuity it is very easy to set something up.
Even with all these precautions things can still go wrong. So if at all possible try to get a knowledgeable reefkeeper to tank sit if you can but if not, minimise the risks. I have had to leave the tank now on a number of occasions, but thankfully nothing untoward has happened. In fact I am sure the tank always looks even better when I return.Or is that just a case of absence makes the heart grow fonder?
Sarcophyton Propagation
As the tank grew in age, it became clear that many of the cuttings that had initially been almost too small to see were rapidly outgrowing their allotted quarters. This was perhaps most noticeable with the Sarcophyton. By April 2001 it was fast approaching being nine inches across and was putting many other corals in its shade. Something had to be done. Unfortunately, it was attached to one of the biggest rocks in the tank, so moving it was not an option (even if it had been there was nowhere else for it to go!). So cutting it to reduce its size was the only course open to me.
With this being the largest coral in the tank I must say I approached the cutting with more than a little trepidation. After stroking it to get it to withdraw its polyps, I used a Stanley knife blade to cut a 4cm wide band from its circumference. This band was then cut into 14 segments, which in turn were mounted onto pieces of rock.
I used one of two techniques to do this. The first was good old super glue gel. The other approach was to use a needle and fishing line and sew a segment onto this and then tie it to a rock in such a way as to hold the cut surface snugly against the rock. The cuttings were then placed around the tank, but as there was so many I quickly ran out of places to put them.
In order to create space I bought two clear plastic breeding traps and secured them to the central cross piece of the tank. The remaining cuttings were placed in these. I have since found these clear plastic breeding traps to be a must have piece of equipment for coral propagation. They allow cuttings to receive a gentle flow of water while they attach and should they become detached, they remain in the trap rather than getting lost in the tank. Following the cutting of the sarcophyton I was surprised how quickly it recovered. Within a few days the polyps were again extending on both the mother coral and the cuttings and within 2 months it was hard to tell that the mother coral had ever been cut. In fact it is growing at such a pace, I anticipate having to repeat the process before long. The only negative aspect of the whole process was the effect it had on my two clowns. They had adopted the sarcophyton as their surrogate anemone but after the cutting they stopped using it as their home and became very aggressive towards my Cherub Angel. Fortunately he was able to hold his own and after several torn fins a pecking order was once again established. The clowns then took a fancy to some hairy mushrooms before finally taking up residence in one of the cuttings.
Misconceptions about cement rock tanks
I read a number of the reef related bulletin boards and am often surprised by what is said about cement rock reefs as it rarely reflects my experience of keeping one. So to finish off this series of articles I have brought together some of the most commonly stated misconceptions taken as direct quotes from posts.
"It should work fine as long as you do not plan to stock it with fish. GARF do not have reefs they have coral gardens."
My tank has seven fish. A pair of Common Clowns, a Yellow Tang, an Orchid Dottyback, a Cherub Angel, a Banggai Cardinal and a Red Headed Goby. They were introduced gradually over the course of the first year and have been in there ever since. So I disagree with this view, you can stock GARF style tanks with fish.
"The problems with those tanks usually are an ever increasing pH, inadequate lighting, and poor biological filtration."
"Concrete rock is heavy, it is chock full of hydroxides that can leach for years, and its porosity is lousy compared to biogenic carbonate "live rock."
During the first two weeks of setting up my tank I did witness an alarming elevation in the pH but this quickly stabilised. Since that time I have not experienced any problems whatsoever with increasing pH levels. I think providing you cure your rock adequately, you will not have any problems with ever increasing pH. As for cement rock being heavy with lousy porosity, nothing could be further from the truth. The recipe I used produced rock so porous that water flowing from a tap runs straight through it. Also, when you lift a piece, heavy is not a word that immediately springs to mind. Finally, I have not had any concerns regarding the biological filtering capabilities of the rock in my tank. Whenever I have tested for nitrates, they have been undetectable. Clearly the rock is performing its function admirably.
"The GARF method leads to a limited, not terribly productive reef. Yeah, it looks like you save some money. But really, you do not, because you end up throwing all that out and getting real equipment eventually anyway."
If your aim is to stock a reef with acropora and other high light demanding corals then clearly trying to do that with three or four 40W tubes is a recipe for disaster. However if you use a bit of common sense and stock according to the conditions you can provide, then the result is a very productive reef. I have to regularly make cuttings of my corals in order simply avoid the tank becoming overgrown with them. It is not what I would call "not terribly productive".
Conclusion
I hope these articles have proved informative and given an insight into an alternative way of setting up and running a successful reef tank. With a little thought and patience it can easily be done. So why not give it a go!