The reef aquarium is the most popular within the marine hobby and there are considerable numbers of aquarists who keep fish only systems. I don’t know what the actual ratio is.
Keeping either type is fascinating and has advantages, the reef system with its beautiful corals and fish, or the fish only with larger fish or numbers. The reef system attracts because of the mixture of livestock and the fish only because fish that are predatory and/or larger and/or reef unfriendly can be kept.
A comment was made a good while ago in discussion about the different marine systems – I think it was at the local fish shop over coffee – that it would be terrific if both types could be kept. Well, of course they can however there is a larger demand on space. Two aquariums are required and maybe two sumps to go with them.
As the discussion developed the suggestion was made that perhaps the two types could be kept in one aquarium. ‘Err, how is that done then?’ was the general comment. The answer was to divide the aquarium down the middle front to back. It wouldn’t cost much, just some silicone sealant and a sheet of glass. It would be easier to do at the setting up stage, though with considerable upheaval it could be done later. It was agreed that a sump would be very desirable to increase the net gallonage of the total system, and the sump should be as large and as deep as possible.
The discussion was becoming quite excited as the idea was expanded.
The lighting and seawater circulation was sorted out, the lighting being suitable for a reef on the reef side and reduced lighting on the fish only side, understandably enough. The sump which was nearly as long and as wide as the display aquarium would contain a deep sand bed and all the heating equipment plus a protein skimmer. There would be two seawater return pumps in the sump for each side of the display aquarium.
The necessary size of the display aquarium caused some head scratching. ‘As big as possible’ was obvious, but what would be the minimum size? If too small the reef would not be very extensive, though it has to be remembered that there are some really good and interesting nano systems about. The size of the fish only side would dictate the type of fish that could be kept. Butterfly fish would be my choice and so about three feet. It was decided that six feet would be pretty good with four feet about the minimum.
Some paper was scrounged and the basic system laid out, it looked pretty impressive with the equipment shown plus overflows for seawater etc.
Two of us weren’t convinced. A bell was ringing in my head, ‘something wrong’. I stared at the paper and then it struck me. I said ‘I think we need three more items.’ This got attention, and feeling rather guilty I said the extra equipment would be another protein skimmer, another heater and another sheet of glass.’ The other aquarist who wasn’t convinced smiled and nodded. I went on that the extra sheet of glass would be to divide the sump so that in effect there were two, the extra heater and protein skimmer would go in the side of the sump that didn’t already have them. There was some realization of what I was getting at, but not overall.
I pointed out that the idea had effectively been made into two systems and the reason was that one thing had been overlooked, this was seawater quality. If the reef and fish only were combined within the sump then the seawater of each would mix. Fish only systems usually are more heavily stocked thus requiring more feeding, which in turn causes an increase in pollutants, the obvious ones being nitrate and phosphate. The seawater quality would reduce for the reef, though probably that in the fish only could be enhanced. Seawater quality is the number one requirement for both systems, with the reef requiring the highest quality.
The system with the extras would work, provided the aquarist had an aquarium big enough – meaning provided there was enough space available. It would certainly be pretty impressive and different. There wouldn’t be many aquarists though who would be willing to reduce the overall reef or fish only display. It was agreed that the way to ensure ongoing top-notch seawater in the original system with an undivided sump would be to increase the gallonage of the routine changes.
The shop owner offered another coffee and a laugh was had. The discussion was great. That’s a big part of the hobby, ideas, discussion and friendship.