There are jobs that can take up time with a marine aquarium whether the system is fish only, corals only or mixed reef. Some of these jobs cannot be automated, such as cleaning the algae off the viewing glasses. However there are some straightforward basic tasks that could be.
Light is essential on all systems though the type of light (the spectrum) is particularly important on corals only and mixed reefs. Light itself is important on all aquarium types as it provides the rhythm of life – when it goes dark fish find their hide holes and corals could start to close. At the same time night life could appear such as the tiny creatures in the rocks and sand. Light is the first item to automate – most aquarists do but there are those few who turn it on and off manually which is not recommended. First there needs to be a set pattern or rhythm to ‘on’ and ‘off’ periods, livestock need this in the same way that humans do. The lighting ‘on’ period needs to the same day after day, with corals this is set to the length of time the corals need. All that is needed are electric timers, usually two. Why two? It’s very bad practice to plunge a dark aquarium into bright light or vice versa as this is very unnatural and causes some livestock panic. Fish for example need time to settle and go to their night time abodes where they have security. Daytime doesn’t start with instantaneous sun-up but there is a gradual increase of light. Coral only and mixed reef systems usually (but not always) employ strong white lighting and also blue (actinic) light as the latter is very useful to corals. So if the white light is turned on by one timer the blue can be turned on by another. The blue comes on around 30 minutes before the white and turns off about 30 minutes after. Though not a proper dawn and dusk this is sufficient for the ‘night time is coming’ and ‘wake up now’ needs of livestock. A fish only system could have say two white tubes fitted – it’s simple to fit one additional blue tube which enhances the fish colours as well.
Another job that could be automated is seawater level. Maintaining the correct level is important as this has an impact on salinity. It has to be said that topping up manually each day isn’t usually negative as far as salinity is concerned as the amount of water lost through evaporation in one day shouldn’t have a large impact, nevertheless there is an impact. If an accurate graph were to be drawn of salinity levels over say a week, the up/down fluctuation would be smaller with automated top up than with manual as the automated system applies several smaller top-ups in a day. Though it’s probably correct to assume that most marine aquarists (except perhaps those with fish only systems) run their aquariums open that is without cover glasses, those that have cover glasses will lose less water. If the water top-up is to be automated all that is required is a simple system that can be purchased commercially and which are not particularly expensive. These mostly consist of a float valve (to signal when water is required and when water is at the correct level), a small electric pump (to send replacement water when needed) and a water reservoir. Once set up the aquarist need only ensure the system continues to operate correctly and also keep an adequate supply of fresh water in the reservoir. This supply should really be RO (reverse osmosis) water.
There is an important point that should be made about water in the reservoir and this is it must be fresh water not salt water. When water evaporates from the display aquarium it is fresh – the salt is left behind. Using salt water will mean a slowly increasing salinity level. Salt could be lost but this is usually from salt creep, this is when salt encrustation is seen on wires, glass etc. that are close to the seawater surface.
The final basic automation that could be considered by the aquarist is feeding. Experiments have been done where several feeds a day have been injected into the aquarium so that fish can feed more naturally (as opposed to one or two major feeds each day). There have been successes with a few of these efforts but the system is troublesome. The major problem is keeping the food fresh (the foods used are a mixture of ‘meaty’ substances in small bits plus a little very small flake mixed in). The food is in a reservoir which is stirred continuously to keep the food dispersed so it can be successfully pumped to the aquarium and the pump used for this is a very small specialist pump (called a peristaltic pump) that is able to deliver small programmed doses (on the same principle as medical ones that are used to deliver small precise amounts at given times to patients). These are the first problems, stirring the mixture and ensuring the pump isn’t going to block as the tubes used are narrow. The major problem as already said is keeping the food fresh – these foods can ‘go off’ quite quickly. This was overcome by refrigeration – the food to be used was kept in a very small refrigerator from which it was pumped on demand, usually the pump was not inside with the food but a narrow tube (which is the method of delivery with these pumps) came through the casing.
Any aquarist who is not into general experimentation (which includes most of us) can easily see that the effort and expense is not worth the result. Provided an adequate diet is fed and overfeeding is avoided, feeding once or twice a day doesn’t seem to do any harm to most livestock types, though as always there are exceptions such as small mouthed specialist feeders who often can’t compete with bolder greedier types. These more timid types are dealt with on an individual basis by the aquarist.
What about other automatic feeders then? These are available commercially and as mechanisms are generally reliable and not overly expensive. They usually clip to the aquarium side near and above the seawater surface. This positioning could be a problem, the fixing needs to be secure. The devices have several partitions so that one meal or more can be delivered per day at pre-set times. Unfortunately, for the devices to deliver the food it must be dry so it doesn’t clog or stick which rules out some marine foods such as frozen and leaves the choice as flake. Flake is placed in the device as desired and is delivered according to the set programme to the seawater surface. The flake has obviously not been pre-soaked so it floats on the surface for a while anyway. It could be that eagle eyed fish will see it and come to the surface to eat. The problem is that some perhaps most of this floating food could disappear over a weir to a sump or down a surface feeding filter intake and the like. These devices are not desirable in another way – they take away the enjoyment of interaction between the aquarist and the livestock. Most importantly, they could remove or reduce the time when the aquarist watches the fish and notes anything that could be a problem.
There are other more advanced devices that could be automated but above are the basic ones which most aquarists could consider. The one for lighting is considered essential. The one for water top-ups is for the aquarist to decide, many find it easy to top up each day though circumstances and aquarium size vary. The one for feeding is easy to consider – the first refrigerated method is more than most aquarists need or are willing to cope with. The second simpler flake feeder devices could be useful, but if to be considered it’s suggested that one is seen in action first on a friend’s system. If impressive enough then consideration needs to be given to security of delivery which depends on individual systems – the food needs to get to the fish and not be gathered up in a sump or filter.