Published Articles

In order to maintain optimal water quality parameters, specifically with dissolved nitrogen waste products, an aquatic system must have a functioning biofilter. A biofilter is a specific unit within the system’s process flow where water is directed and treated using beneficial microorganisms intentionally grown on specific media. It can be a challenge to jump-start and cycle a biofilter in a new aquatic system.

When deciding to either enter the RAS world or modify existing systems, it is important to consider several things.  Here’s the caveat: to be clear, this article is not exhaustive nor am I willing to make the statement that it includes everything.  Now that we have dispensed with that, these are the items that consistently crop up during discussions with colleagues and customers.

This issue’s column is focused on centrifugal pumps.  They are the most widely used water mover in our industry and in most cases the most misunderstood.  In theory, a 2hp pump is supposed to draw 2 HP to operate properly regardless of who manufactures it.  However, not all pumps are equal. Many pump manufacturers “play” with the HP number by not adding in the efficiency of the motor to obtain wire-to-water HP.

One of the most important components of a system and in many cases, the least understood is biofiltration.  While the calculations for biofilters are published in several textbooks and a multitude of professionally reviewed papers exist on the sizing of them, there is still a lot of fuzzy logic that gets used in the industry.  The challenge is understanding the pitfalls of improperly sized biofiltration.

Instead of focusing on a particular type of equipment, I thought it might be good to get back to basics and discuss electricity and the power options we have when we are putting together our facilities. It is important to review both capital expenses and operating expenses when selecting equipment. The cost of installing different power supplies varies by location and type. 
One of the most frequent comments I hear is that every application should be with three-phase power. The reason I am consistently given is that it is cheaper. Let’s examine this closer.

Over the last year or so we have been focusing on both specific products and inputs to systems.  Our hope is to bring out some of the lesser known details on how things work. An important detail that is often ignored is pipe sizing.  In many cases, the end user will choose to use the same size pipe as the inlet or outlet of the pump or blower that they are installing. The thought process is often along the lines of “well if it needed a bigger pipe, wouldn’t the manufacturer make the inlet or outlet bigger?”  The answer is generally no.

When it comes to disinfection in fish systems there are a couple of approaches designers and engineers use.

Chillers and heat pumps are not always necessary in aquaculture, but they are needed when consistent temperatures are critical to animal growth.  With an increase in the number of recirculating systems being built, they are becoming a necessity for growth control.  Both work on similar refrigeration principles but this article will address them separately.