The Protein Skimmer - What Is Wet And Dry Foam?

In a saltwater aquarium there are various devices that are designed to assist in the maintenance of high quality seawater. Perhaps the most useful of these is the protein skimmer (ignoring bio-filtration).

As with all devices for it to be at its most effective it must be adjusted correctly. First though, the skimmer must be appropriate to the size of the system.

The normal way of sizing a skimmer is to simply double the net gallonage of the entire system, then find a skimmer that can deal with about that amount. This is a guideline only, and is designed to overcome the sometimes optimistic claims of manufacturers. As long as the skimmer is not a long way short of the guideline it should suffice. Having said that, some manufacturers seem to be more realistic of late with the potential performance of their skimmers.

Skimmers are available as ‘hang-on’ and stand alone, and it is the aquarist who decides which is the most practical. For example, if there isn’t a sump then a ‘hang-on’ is probably the best choice.

It is also important to ensure as far as possible that the model chosen is a good one. Internet forums are useful for this, though there are likely to be some differences in opinion. Maybe more useful, sometimes a local retailer has hobby-sized skimmers running on aquariums, and these can be judged quite easily. First of all, look at the chamber where the bubble/water interaction takes place. The bubbles should be very small and in very great numbers - the bubble chamber should be full of them and coloured white (ish). One respected manufacturer states that the important things about a skimmer are ‘design, air output, air output, and air output.’ Also look at the collection cup, hopefully the skimmate (the dirty liquid inside) will be dark coloured. (This colouration has a lot to do with the way a skimmer is set-up and the amount of dissolved organics available, so a visual check is not entirely reliable.)

So the foam. This is the foam that forms at the surface of the bubble chamber and rises up the throat towards the collection cup. In a badly set skimmer, foam rises very rapidly in the throat and dribbles nearly continuously into the collection cup. The foam can be seen to collapse immediately or nearly so. The skimmate collected is weak in colour and thin. The cause of this is usually the bubble setting, where the amount of bubbles being produced is too high. This is the so-called wet foam.

At the other end, the foam may not rise very much at all, but when any gets into the collection cup it is thick and dark. The foam can be seen to be stiff, and is very slow to collapse. In this case, the setting is not far from being correct. This is the so-called dry foam.

The general ideal is where the settings produce many bubbles, but the foam does not get into the collection cup all the time. The foam may rise up the throat only to fall back when the rise begins again, and it is stiff and not too quick to collapse. When dissolved organics are present, the foam rises and enters the collection cup readily. It is dark, thick and can be smelly.

The manufacturer’s instructions should be followed initially, setting the device as suggested. Make sure the foam does not flow into the collection cup too rapidly, but allow the skimmer time to settle for a few days, as foam production is often affected by the manufacturing process. Once this time period has passed, trial and error will show the best settings for an individual aquarium. There needs to be good bubble production, which is controlled by the air intake setting, balanced with the appropriate flow rate.

A skimmer does not usually produce skimmate continuously, but will react to any dissolved organics. Some additives cause a reaction, and the addition of foods, such as some frozen types, usually will too.

Once the settings have been arrived at, usually they can be left alone. It is important to clean the throat (and collection cup) of the skimmer, as the sludge in the throat will adversely affect performance. When cleaning is done, skimmers often needs a short settling period again before full performance returns.

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Tags: Aquarium Water, dissolved organics, Equipment, foam fractionation, Protein Skimmer, Water Quality

Should You Run Your Protein Skimmer Full Time Or Part Time?

The protein skimmer assists in the removal of dissolved organic compounds (DOC’s) from the water column. The protein skimmers manufactured nowadays are normally exceptionally efficient - as long as they are kept clean!

So what do I mean by running your protein skimmer full time or part time?

Well basically a protein skimmer which is run full time is turned on 24 hours a day 7 days a week whereas a part time skimmer is on for less hours in the day - 12 for example.

So why would anyone consider this?

You have to look carefully at what you are keeping in your saltwater aquarium. If you are keeping fish only then I would recommend without hesitation that the protein skimmer be run fill time. Fish produce a lot of waste and we have to feed them so the protein skimmer assists in the removal of these items as well as others from the water.

If you keep a coral only or a mixed reef tank then perhaps it could be different. I say the word perhaps as you need to look very closely at what you keep in your aquarium. The reason for this is that we are interested in the load on the aquarium i.e. how much waste is being produced which the protein skimmer can then process. In a coral only aquarium then very little bioload should exist as corals put very little strain on the system. This does not mean that you do not need a protein skimmer as I personally would never have a saltwater aquarium without a protein skimmer installed.

In a mixed reef aquarium then you obviously have corals and fish, therefore like the fish only aquarium the fish are being fed, due to the feeding waste is produced which could easily impact water quality. Yet, how many fish are in the aquarium? How large are the fish?

What you can do is review your protein skimmer over a couple of weeks. Ensure that you have optimum water quality and then check your collection cup at the end of the period and see how much waste has been produced. If the cup is over half full then realistically you probably need to keep the protein skimmer running full time to ensure that everything is removed. If the cup is less than half full then faesibly you could potentially use a part time skimmer.

Of course this is not set in stone as each aquarium system is different. The decision ultimately comes down to you based upon your particular setup.

So why do it?

There is a lot of debate as to how much good is removed by a protein skimmer as well as bad. As protein skimmers have evolved over the years they have become more and more efficient. Due to this efficiency they can remove a huge amount from the water. This is great in one way as it assists us in both creating and maintaining the water quality which our aquarium inhabitants require however what else is removed?

Personally I have absolutely no idea. I am not a scientist and do not have the tools, skills or knowledge to be able to analyse the output from a protein skimmer and see what it contained. All I know is that it is brown and exceptionally stinky!

It is believed that some of the items potentially removed by the protein skimmer is used by corals as food. Corals receive the majority of their energy from the lighting which is provided to them, however they do receive a good amount from food captured in the water. This could be the likes of phytoplankton, zooplankton etc. Have you ever watched a documentary on the television about natural coral reefs? Have you seen how many particles are floating about in the water? Loads aren’t there - in the aquarium we do not have this amount as we have to use man-made devices in order to keep the water clean.

So potentially if you run the skimmer part time some of this life will not be removed and can be used by the corals as food.

There have been reports that when this is performed it has been noticed that the corals appear to have better colour and better polyp extension.

Another method is by actually feeding the corals yourself. You can purchase various ready made containers full of coral food which you feed to the aquarium. There are also various methods you can follow to make your own coral food. I will cover coral feeding in a future article.

Would I do it? - maybe but only if I was absolutely positive that it was not detrimental to water quality and I would be testing the water all the time.

Would I recommend the beginner do it? - Probably not - not just because they are new to the hobby but the aquarium is also new and needs to age a bit. Perhaps if only corals were being kept but even then I think that it should be run full time until the aquarists gains experience.

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Tags: aquarium food, Aquarium Maintenance, Care, Corals, Equipment, marine reef, reef-tank

Quick Tip - Don’t Forget To Clean Your Protein Skimmer

A protein skimmer is installed onto the aquarium so that it can remove substances from the aquarium water so that we can keep water quality at an optimum.

It is imperative that a skimmer runs at full efficiency in order for it to work correctly. For this to be achieved it needs to be thoroughly cleaned.

You will be surprised how many people simply remove the cup from the skimmer, pour the contents down the sink, give it a wipe and put it back on the skimmer again.

Not good enough I’m afraid.

Although the contents have been removed and the inside of the cup has been wiped there is one very important part which has been missed.

The rising tube of both the skimmer and the cup itself.

If the rising tube is not cleaned then it will become coated and the skimmer will not operate at full efficiency, therefore optimum water quality is harder to maintain.

What I do when I clean my skimmer is:

1. Empty the contents down the sink (and the clean the sink afterwards to keep the missus happy!)
2. Using a bottle brush give the inside of the cup a good clean and then wipe clean with a cloth.
3. Using a bottle brush clean the underside of the cup ensuring that the riser tube is clean and then wipe clean with a cloth.
4. Clean the cup lid with a cloth.
5. Using a bottle brush clean the riser chamber inside the skimmer itself.

The above does depend upon what type of skimmer you use, however the majority of skimmers can be cleaned in this way.

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Tags: Aquarium Maintenance, Care, Equipment, marine-aquarium, Protein Skimmer

Is A Protein Skimmer Actually Required?

The fish only aquarium or reef aquarium has a number of devices designed to help maintain the correct parameters, hopefully ensuring healthy livestock with a long life. These are heaters, water level controllers, calcium reactors, lighting controllers etc.

All of these devices service a particular area. For an obvious example, heaters maintain temperature. The action of these devices is appreciated by the aquarist as the action is usually obvious. There is one device though which sometimes causes doubt, and that is the protein skimmer.
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Tags: aquarium, Equipment, home-aquarium, Protein Skimmer, saltwater-aquarium

Choose The Best Protein Skimmer You Can Comfortably Afford

Obtaining equipment for the fish only or reef aquarium is an important step on the journey towards success. Research again is the key, rather than purchasing an item that ‘should do.’

A major item of equipment for the marine system is a protein skimmer. This device removes dissolved organic matter completely from the aquarium seawater. Why is this so good? The organics are removed before they are acted upon by the natural processes in the aquarium when they are eventually turned, up to a point, into nitrate. So, the more efficient the skimmer the less pollution.
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Tags: Aquarium Filtration, Equipment, Protein Skimmer, saltwater-aquarium, skimmer

What does a protein skimmer do?

Protein skimming (foam fractionation) is actually another type of filtration.

Protein skimming allows for the removal of certain types of DOC’s (dissolved organic compounds) from the water. What happens is that very small bubbles of air are passed through the salt water - this occurs inside what is normally called a reaction chamber. The organic matter in the water ’sticks’ to the side of the air bubble and rises up with the bubble. Once the bubble reaches the top of the chamber foam is created. Over time these organics get pushed higher and higher until eventually they rise and fall into the collection cup of the skimmer ready for emptying by the aquarist. [Read more]

Tags: aquarium-marine-protein-skimming, aquarium-protein-skimmer, nano-protein-skimmer, saltwater-protein-skimmer