Modifying a Protein Skimmer

Protein skimmer modding is such a popular method of increasing a protein skimmer’s performance that even popular manufacturers have taken notice. The goal of the modifications is to increase air intake, make finer bubbles, and get much darker skimmate production.

The first modification I would like to discuss is opening up the venturi adapter to let more air in. The venturi adapter is located on the suction side of the skimmer pump and sucks air into the water where it is chopped up by the needlewheel impeller. It works just like a snorkel when people go diving. Modifying the venturi is a simple task, but requires a little hardware. A drill or rotary tool is all you’ll need. Simply insert the drill bit into the opening where the flexible tubing attaches, and get to work. I would slowly increase bit size until you have reached the desired size of the opening.

Modifying Protein Skimmer Venturi Adapter

*Photo Courtesy of The Talking Reef

Another way to modify the venturi is to open up the volute. The volute is the portion of the venturi adapter that allows water into the pump. If you open this up a bit, you can allow more water and air into the skimmer. Like opening the venturi, this mod requires some tools. I prefer the rotary tool in this case above all else. And like the previous mod, slowly increase the size of the bit so that you can get to the diameter you are looking for.

A third way to modify the venturi assembly is putting a valve on the flexible tubing attached to the venturi adapter. A lot of skimmers come with this already, but a lot of skimmers don’t. By adding the valve, you can cut back on the amount of air entering the skimmer in order to find the “sweet spot” where you get the most consistently sized bubbles or the right about of air to water mixture.

The next, and probably most popular modification is the use of a mesh wheel on the impeller. Most stock needlewheel impellers utilize various projections (called needles) coming off the wheel in order to chop up water. The needles are usually uniform in size, shape, and spacing, but do a pretty good job of chopping up the air and water. But to get a finer sized bubble, many people attached Enkamat or Gutter Guard to the needlewheel. Enkamat is a plastic-based product that was originally used as a root reinforcement materail for laying grass in high erosion areas and is a very non-uniform material, unlike the traditional needlewheel. The mesh mod is achieved by cutting off all but four of the needles, drilling holes next to the stock holes on the wheel, and putting a few layers of the Enkamat or Gutter Guard onto the wheel and attaching them with zip ties. The zip ties will be fed through the holes you drilled and the holes already present on the needlewheel. After the mesh has been attached, simply trim it to be the same shape of the needlewheel so that it fits into the pump without rubbing.

Picture of Enkamat

*Photo Courtesy of Marine Solutions

But be careful when using the mesh mod. If you do it improperly you can cause the impeller to be unbalanced when it spins and could cause the impeller shaft to break or bend. Also, the mesh can rub or get caught on the housing of the impeller. Another common problem with mesh mods is the inability of the pump to start back up properly after the pump has been turned off. The mesh gets caught and the impeller won’t spin.

Modified Meshwheel Impeller

*Photo Courtesy of Melev’s Reef

The previously mentioned mods (the venturi and meshwheel mods) are the most commonly used modifications. However, there are several more. Some people utilize a recirculating mod whereby they add a pump (or alter their current one) to be able to run the skimmer externally, or just for the purposes of adding another pump, or to alter the current setup. Aquarists who advocate the recirculation setup (either factory or modified) say that recirculating skimmers perform better than in sump skimmers.

Modified Recirculating Protein Skimmer

Standard Recirculating Protein Skimmer

Some people also increase the length of the protein skimmer’s neck. This mod will cause the skimmate to be drier and will also help the skimmer to accommodate the first two mods a little better. Lastly, some people add a bubble plate inside the skimmer’s main chamber. The bubble plate is a fairly new feature that manufacturers are adding to their protein skimmers. They function by decreasing the turbulence inside the skimmer, allowing better bubble formation and enhanced skimmer performance.

Bubble Chamber Modification

Bubble Plate Modification

*Photos Courtesy of The Talking Reef

The last skimmer mod I would like to talk about is the gate valve mod. Like some of the other modifications, the gate valve has found its way onto a lot of straight-from-the-factory protein skimmers and functions in allowing the user to better control the water level in the body of the skimmer. This valve is added to the output side of the skimmer, and closing this valve will raise the water level in the skimmer.

Gate Valve Mod

*Photo Courtesy of Marine Solutions

These mods will all improve skimmer performance in some way. It may take some time to break each mod in, but these will all cause the pump to pull more air, create more bubbles, and make some nasty skimmate.

Sources:
Talking Reef
Melev’s Reef
Marine Solutions
The Reef Tank
Oceans At Home
Aquarium Specialty
Marine Solutions