Saltcorner
By Bob Goemans
By Bob Goemans
Dear Bob,
I have been operating an aquarium service in the LA area for the past ten years. The plenum filter system has seemed to work well with the invert dominated tanks. My question is to what advantage could the plenum system be used in a fish only aquarium. Many of my clients enjoy large angels, tangs, eels and groupers. Housing these animals and processing their waste would need a large bio filter such as a wet/dry.
Could you (or would you) use a plenum with a wet/dry?
Thank you,
Kim Koch
Hi Kim,
That's a good question and I can understand where you're coming from. It would seem reasonable to think filtration equipment such as trickle filters and fluid bed filters would be the best way to handle the bioload generated by large animals or in a heavily stocked fish-only system. Yet, some very knowledgeable folks are now rethinking that wisdom!
The Oceanographic Museum of Monaco has a full-sized coral reef system called the "Lagoon of Sharks.' It features a coral reef on one side and a deepwater area on the other side for big predatory sharks and rays. This whole structure is two stories high and 33 feet by 30 feet wide and holds about 100,000 gallons. It is divided in half by an acrylic panel with each section separately filtered because they did not want the pollutants generated by the large animals to affect the more delicate invertebrate in the living coral display. However, each side is filtered by the Jaubert plenum method, with additional sand filters used on the large animal side. Both systems also receive a 1% natural seawater exchange hourly. Nitrate readings remain a little high on the large animal side, but its anemones, clownfishes and cardinalfishes have reproduced and are forming large colonies. As for the living coral reef side and its more delicate inverts, its water quality remains perfect.
And, about two years ago I helped a shop in England set up their filtration system with a very large plenum. In fact, it's 16 feet long and five feet wide and you can see a photo of it on my website (www.saltcorner.com). They have 1000's of gallons of fishes, corals, and live rock all filtered by their plenum system. And, their nitrate reading throughout their systems is usually barely readable! Prior to that, about three years ago, I did the same with a local shop. Their system nitrate level was almost always 2 ppm or less.
But it should be kept in mind these plenum systems are dedicated systems with wide-open sandbed surfaces, and they work well! Yet, in individual hobbyist tanks containing a heavy fish-only load, I would still consider using trickle filters and/or fluid bed filters, which are easier to service than a sandbed. Besides, fairly high nitrate levels won't affect most of these fish. This is not to say the plenum method would not work, but in your line of work, time is money. And you want to be in and out without too much system tweaking. Hope this helps,
Bob
