Revolutionary or Reactionary?

It's easy to condemn old ideas in fishkeeping as old-fashioned and out-dated. Sometimes they're still sound, and with the benefit of new technology, can be spectacularly successful in a way they never previously were.

One current debate in PFK concerns the effectiveness of "modern" and "traditional" marine filtration systems. The pace of progress is so rapid in marine fishkeeping that modern and traditional are relative terms.

Modern systems are developments of the living sand and living rock systems, both of which rely on the "natural" removal of wastes without masses of mechanical filtration. Protein skimmers (foam fractionators) play a major part in these systems, but aside from powerheads to produce surges, little other equipment is used. In the UK monetary savings are non-existent, at least in living rock systems, as the large amounts of rock required are exceedingly expensive.

Apostles of these modern systems say that nothing compares with this natural filtration. Nitrate removal is especially good, as below the living sand in a plenum of oxygen-free water, or deep within the interstices of the living rock, de-nitrifying bacteria break down the nitrates, releasing harmless nitrogen gas.

In the new "green" world where "natural" is always best these methods have world-wide fans, the decision to use them being both practical and I suspect, emotional.

In the UK, these methods were slow to catch on. Even our own marine contributors were, and are, distrustful of the new and conservative in their acceptance of the new ideas. But four or five years of publicising the systems in PFK are beginning to have an effect on living sand, living rock and hybridised systems incorporating other filtration methods are achieving new popularity.

The only drawback to this method is only recently being discussed in the UK. Calcareous rocks appear to adsorb nitrates and phosphates over a long period and may begin to dump them back into the tank. This phenomena has recently been dubbed "old tank syndrome". Fans of the "living" systems will no doubt point out that nitrates shouldn't build up in the tank in the first place, with light feeding, protein skimming and the anaerobic activity in the living rock.

The cap and whippet view of England's north -especially Yorkshire and Lancashire - sees the area as totally traditional and resistant to new ideas. For lots of reasons, the greatest probably being traditional Northern cynicism, the cap fits - and for lots of other reasons it's patently nonsense.

Let's say that Northerners are acutely aware of the difference between an innovation and a gimmick. Stubborn adherence to the "old" trickle filter (wet and dry media) with the (not entirely) "modern" tweak of a submerged chamber of sintered glass media for the nitrate-reducing anaerobic bacteria, has characterised Northern marine systems (or so our York-based correspondent Les Holliday has it.)

The only drawback has been the nitrate-adsorbing qualities of those traditional piles of tufa rock laid in to aquascape the tank or the calcareous rocks that the inverts attach to. It's now claimed that the use of modern inert synthetic rocks - the so-called lava rock among them - will avoid the dumping of nitrates and the "old tank syndrome" while an anaerobic sintered glass underwater compartment will break down nitrates making for ideal water conditions.

It now remains for aspiring reef-keepers to balance the costs and demands of high quality trickle filtration with all its pumps and sumps against top-quality seeded living rock.

© Steve Windsor. May not be reproduced in part, or whole, without permission.