Consider Before Buying

Marine aquariums are great. They make a terrific hobby and it really can feel that there is a ‘slice of the ocean’ in the home.

The marine aquarium comes in two main forms – the fish only system and the reef system. Most aquarists opt for a reef system and it is easy to see why. The desirability of a fish only system is a very close second (in my opinion) and they are owned by a lot but not as many aquarists. Some aquarists have the best of both worlds, they have one of each. Envious? No, of course I’m not. I hope that sounded convincing!

Buying livestock is very exciting. This happens when the new aquarium is set up, with seawater added and a bio-filter operational. The heaters, pumps, protein skimmer and the rest of the support equipment are running satisfactorily. So off to the retailer goes the aquarist.

Having spent the time ensuring that the equipment is suitable for the job and spent what could be a small fortune it would be a shame to spoil things now, but it does happen. In go unsuitable corals and unsuitable fish. It is clear why this can happen. The corals and/or fish look so beautiful in the retailer’s display aquariums. The corals are fully extended and in good health and the fish are in good colour and quite small. In the home aquarium this could change quite quickly.

First, new aquarists often stock too quickly, and the effect of doing this is most noticeable with fish. At first the fish seem fine and it is so, so good to see them cruising about exploring their new home. Feeding is done and at last the aquarist feels that he/she has achieved the objective – a fine marine display.

Then fish start to act oddly. The aquarist continues to feed and, as matters become worse, resorts to forums on the internet to obtain advice. Hopefully matters will be sorted quickly, but often they are not. Some fish die, maybe all of them. It is easy to feel the aquarist’s pain.

What happened? Unfortunately in all the excitement the fish went into the aquarium too quickly and the bio-filter couldn’t cope. The hard working bacteria that operate the Nitrogen Cycle didn’t have time to adjust to the fish load. Consequently the fish were exposed to toxins, namely either ammonia or nitrite or both.

Fish need to be introduced to the aquarium slowly which will give time for the bio-filtration to adjust. It is not just the fish it needs to cope with, but the food they require. Not all of this food is consumed and some will rot and add to the bio-load.

It is best to have a list of the fish types that are desired. This list can be as long as required; there isn’t any need to restrict the number of fish types. Try and get them in order of desirability and having done this get into some research of a more serious nature. How many inches of fish (exclude the fish tail when considering fish length) will the aquarium be capable of holding? This is controlled by the net gallonage of the display aquarium (exclude any sump) and the capability of the bio-filter. A fish only system will hold more than a reef system. With this number in mind, check how big the desired fishes will grow, starting with the fish at the top of the list. This will remove some fish as being unsuitable because of size. Now check hardiness – delicate fish are not really suitable for the beginner. Then check how each of the remaining fish lives – maybe they for example are cave dwellers or open water swimmers. If cave dwellers is there enough accommodation for them. If open water swimmers do they need a lot of swimming room, as do surgeons as an example? All of this could remove more fish. Now the list is shrinking. If it is within the acceptable number of inches, great. If not, the aquarist will have to chew his/her lip and cross more out. There is one more check before the final list is ready, and that is compatibility. Fish for health need to live with a sense of security and reasonable friendliness towards each other, though there will always be some bickering. If any fish are shown as incompatible they have to go. Check each fish against all the others. There are compatibility charts available (there is one on this website).

Now the list is ready there is one more item that is important to know. Which fish are timid and which are bold? Timid fish should be introduced to the aquarium first so they can become accustomed to their home and settled. Then bolder fish can move in.

Remember the fish should be introduced to the aquarium slowly over a period of time to permit the bio-filter to adjust.

So what about corals – surely they don’t need the checks as outlined for fish? The answer is yes and no. There obviously isn’t any need to worry about swimming space and similar, but some research is required. The aquarist has decided what type of corals to keep already as the appropriate lighting for them (and aquarium depth) has been obtained. Again draw up a list of desired corals, the ones really fancied at the top. Then start the research. The very first check required is to check the difficulty level of the coral, as some are hard to keep even for advanced aquarists. Some types just repeatedly fail. Then consider if they are suitable for the environment that has been created, if they need light and if enough is available, and what kind of seawater currents they prefer (weak, medium, or strong). Remember that some corals may prefer a position lower down or higher up – check there is room.

Corals present a much smaller challenge to the bio-filtration. It is worthwhile though placing corals in the aquarium at a steady and fairly slow pace. This will allow time for them to expand and the aquarist will see if there is a placement problem. Different type corals should not touch. Remember that they will grow (though many can be ‘fragged’* and reduced in size).

These checks, both for fish and corals, may seem at first to be rather comprehensive and likely to be time consuming. Well, they are fairly comprehensive but finding out the answers to the questions is not difficult. It is best if the aquarist has a comprehensive marine book or books that covers many aspects of aquarium husbandry, and also gives details of many fish. Many books include the more popular fish and information about them. In the same way many corals are described and the maintenance requirements for them.

Spending time on research so that suitable species of fish and/or corals are obtained in the first place is going to have a reward – it is more likely that the aquarium will be a peaceful successful community.

If the temptation arises months or even years into the aquarium’s life to obtain new additions, the same checks are needed. Don’t buy through temptation. Many do, and many regret it.

(* ‘Fragged’ or ‘Fragging’ = the practice of taking a fragment from a growing and healthy hard or soft coral in order to produce a new coral.)

  1. You’re absolutely right. I went through the same process.

  2. Wish I would have read this before I started in the hobby. lol

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