A Beginners Guide to Protein Skimmers

March 8, 2020

Hi again everyone, let’s talk about protein
skimming. This video is geared towards some of the beginning
hobbyists who may be unfamiliar with all the different pieces of equipment that go into
a reef tank. In my opinion, protein skimmers are one of
the most important devices for a reef aquarium. Can you set up a tank without one? Sure. You can do a lot of things in this hobby and
still be successful. Would I recommend that? No. A skimmer is one of those devices that just
make the hobby easier. I often try to remove technology from my systems
here at Tidal Gardens because we try out a lot of things and over time there is just
too much stuff in the system. I think there is an elegance to removing “stuff”
and figuring out what is really necessary. So in that sense is a skimmer “necessary?” I think that need is a strong word. So I’m going to say no. But, it is one of those things that has such
overwhelming benefits that removing it is just not worth it. So what is a protein skimmer? To put it simply, it is a controlled overflow
of dirty water. Imagine a chamber that vigorously mixes air
and water to create a dense foam. The cleaning action is because of the tiny
bubbles. The surface tension of the tiny bubbles attracts
dissolved organic compounds. After a while, a thick cruddy foam collects
at the top of the skimmer and by removing this foam, the water is cleaned because the
dissolved organics are being removed before they have an opportunity to pollute the tank. There are many types of skimmers and they
are grouped together by the method they use to create bubbles. These days most of the popular designs use
a Needle Wheel impeller that chops up bubbles. An older design uses a Venturi to mix air
and water. An even older design uses Airstones and an
air pump to create bubbles. All of these designs work, and it is a matter
of personal preference and the constraints of the system that determine which type will
work best. If you really want to get technical, you can
take a look at a book called Aquatic Systems Engineering by Pedro Ramon Escobal. There are equations in there that look at
flow rates, and contact time to help determine skimmer efficiency, but to simplify things
a bit for this video bigger is going to work better than smaller, and more contact time
is going to work better than less. Practically speaking however, most installations
do not allow for a massive skimmer. I would venture to guess that most skimmers
in the hobby live in a sump inside the aquarium stand so they are not often taller than 24”. This is part of the reason a lot of skimmers
are now a needle wheel designs and the body of the skimmer is shorter and fatter. I’m calling this section a buying guide,
but I’m not going to cover individual brands or anything. There are quite a lot of skimmers out there
and I haven’t used them all. Still, there are features I appreciate and
would look for a skimmer model that checks off as many of these as possible. First, I want to see a nice pump. A protein skimmer is an incredibly simple
device, and if there was anything that could go wrong and break, 9 times out of 10 it’s
the pump. It’s for this reason I am kind of old school
when it comes to skimmers because I like venturi skimmers powered by a Japanese made Iwaki
pump. They are the exact opposite of an energy efficient
pump, but they are the most reliable pumps I have ever seen. Second, I look at the valve that controls
the water level in the skimmer. Earlier, I described skimmers as a controlled
overflow of dirty water out of your aquarium. Well, the control part of that is very important. If the water level is not high enough, the
skimmer is not really removing anything. If the water level is too high, the skimmer
is removing the dirty water, but also a larger volume of water than necessary. Worst case scenario is it removes too much
water and your return pump runs dry. That’s bad. So, I want to see a nice quality gate valve
to control flow of water leaving the skimmer. When you close down the valve, the water level
rises. When you open it up, the water level falls. A higher quality gate valve will allow you
to do this with great precision. Third, speaking of water exiting the skimmer,
I like to see designs where the water exits above the water line where the skimmer sits. In other words, I don’t want to see the
output of the skimmer submerged. The reason for this is the water level might
fluctuate depending on the system and you want it to be consistent. Assuming for a moment that your skimmer sits
in a tank that has a changing water level, the higher the water level, the more back
pressure is put on that skimmer output. In essence, that is like closing down the
valve raising the water level in the skimmer. This can cause the skimmer to over skim. Once some water evaporates or enough water
is over skimmed out, the water level decreases and now there is less back pressure on that
skimmer output. That’s not a great thing either because
now the skimmer may be under skimming. By having the skimmer output above the water
line, you avoid any chance of fluctuation. Lastly, I want a skimmer that uses the fewest
pumps possible. There are some skimmers out there that use
a whole bunch of pumps to generate foam. Sometimes as many as 4. My problem with these designs isn’t so much
that 4 pumps is overkill, but remember what I said earlier? The most likely thing to break in a skimmer
is a pump. Now that problem is multiplied by 4. You may think that if one fails, at least
you have 3 others as backup! That is better than losing a pump in a single
pump design right? Well… kinda? The problem is, if one fails, the skimmer
still stops skimming properly because it was tuned to the flow rate of 4 pumps. now there are only 3 pumps so that skimmer
doesn’t actually skim until it’s retuned etc. etc. That and I do want a simpler overall system
and skimmers with a million pumps involve a snake pit of wires. Let’s take a look at some common problems
that you may experience with a skimmer. First off, skimmers are sensitive to oils. The bubbles after all work by surface tension
and hydrophilic interactions. You know what could mess with that? Oils. Oils from your hands or from food can shut
down skimmate production for hours. Even a water change can throw off a skimmer
temporarily. There’s not a lot that can be done about
it, you just have to wait it out. Problem #2. A blockage in the pump. This can happen in any skimmer design. A piece of debris that gets stuck in a venturi
or in a needle wheel can throw off a skimmer’s performance so it’s important to regularly
take your skimmer apart and clean it to make sure there are no obstructions. Speaking of obstructions, check the air line
to see if it is blocked. A skimmer’s job is to mix air and water
but if the air intake is blocked somehow, that air water mix gets thrown off where you
are getting more water than air. It’s tempting to just fiddle with the gate
valve to adjust it to calibrate the skimmer, but what can sometimes happen is that obstruction
works itself free and suddenly there is a huge rush of air and your skimmer looks like
a foam explosion the next day. So again, keep your skimmer clean and well-serviced. Thanks again for watching! That pretty much does it for skimmers. Hope that helps you guys with your setups
now and in the future. Don’t forget to like comment and subscribe
if you like this stuff. Speaking of subscriptions, I guess there is
this thing going on with youtube where people don’t get notified about new videos or even
automatically unsubscribed altogether, so if you could, find the bell icon right by
the subscribe button and press that so you don’t miss any notifications. Until next time, happy reefing.

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