Don’t Skimp On Your Protein Skimmer

There are various items of equipment that assist the aquarist, the items differing depending on whether the system is fish only or reef. For example, the reef system, particularly if it is quite large and contains hard corals, could use a calcium reactor - it would be unusual for one to be used on a fish only system.

There are items of equipment that are common to both systems, and an obvious example is heating, normally combined heater/thermostats. Another item that is common to both is the protein skimmer.

The protein skimmer is probably the best equipment aid to seawater quality that the aquarist owns. It therefore makes good sense to take a little care in choosing it.

Protein skimmers use a pump to pass seawater through a chamber where it is exposed to an air/water interface. This interface is created in the majority of skimmers by the use of a venturi valve. Put simply, an air inlet of a particular size is positioned just before the pump impellor. As the pump moves the seawater air is sucked in through the inlet. The air and seawater pass through the impellor where the air is thrashed into tiny bubbles, huge numbers of them. There are variations on this impellor/seawater/air theme but the principle remains the same.

When considering the purchase of a protein skimmer, the first piece of knowledge that the aquarist requires is the net gallonage of the system, which means that the gallonage of the display aquarium and any sump in use should be combined. It is not necessary for this gallonage figure to be accurate, but should be a reasonable approximation if the true figure is not known. Remember it is the net gallonage, that is the seawater amount after displacement by rocks and sand.

The net gallonage of the system is required so that the protein skimmer can be adequately sized. Manufacturer’s quote the amount of seawater that a particular protein skimmer can cope with, and sometimes these quotes are ambitious. The usual method is to obtain a skimmer that is quoted as capable of dealing with twice the seawater that the aquarist actually has. Having said that, of late some manufacturers have been more realistic with their quotes, offering a range of skimmers. Nevertheless, purchase the chosen unit on the plus side, that is, obtain one that is quoted above the known seawater amount.

So which protein skimmer should be obtained? There are two types that mainly interest the aquarist, and these are the ‘hang-on’ and ’stand-alone.’ The descriptions are generally self explanatory - the ‘hang-on’ type is useful for aquarists who wish to place it on the display aquarium but wish to minimise the sight of it within the aquarium, and the ‘stand-alone’ is usually used alongside a sump. Some models are adaptable to both types. Skimmers are supplied with pumps adequate for their purpose.

Having decided the type, the aquarist now needs to pick a model. As with most things, some are better than others.

The skimmer should be properly designed and if skimmers can be seen running then a general simple check will indicate that this is so. The first thing to look at is the bubble generation. Skimmers have a bubble chamber, and this chamber should be a milky white colour, or somewhere near it, and packed with bubbles. The bubbles themselves should be very small. Also listen to the noise of the unit - if it is going into the lounge for example the noise needs to be very low.

Also examine the skimmer and be sure that it is serviceable bearing in mind the location it will be in. For example, during a cleaning exercise the cup needs to be removed from the unit, and this means lifting it upwards. If in a sump, is there room?

When the aquarist cannot see a skimmer operating, then it is best to note down the names of a few types that appear to be suitable. Using the internet, have a look at any reviews that could be available, and note the comments made. Also make enquiries on forums, so that other aquarists who have experience of the skimmer can make a comment. A visit to the manufacturer’s website could also be made, to obtain the specifications of the model(s) of interest.

As already said a protein skimmer is important, and it is very worthwhile giving time for research and checking the performance, as far as possible, of any particular model.

There are other types of skimmer in addition to the venturi models, such as air driven and down-draught types. The venturi skimmers are the most used.

To round off, why is a protein skimmer important? It has already been stated that they are a tremendous aid to seawater quality. This is because a protein skimmer removes dissolved organic matter (DOM). The seawater passing through the bubble chamber will usually be loaded with DOM (the load varies because of circumstances). DOM molecules both repel water (hydrophobic) and are water soluble (hydrophilic). When they are in very close proximity to air, as they are in the bubble chamber, the water repellent part attaches to a bubble. Many molecules can attach to a single bubble in this way.

As the bubbles slowly ascend in the bubble chamber, the DOM molecules go with them. At the top, the foam created because of the attached molecules is stiff, and rises up the neck of the skimmer, and then falls into the collection cup, where periodically it can be removed. Therefore the seawater quality is optimised.

It is important that a protein skimmer is regularly cleaned (the neck and cup) or the efficiency of the unit will be reduced.

The downside of a protein skimmer is that it will not only remove DOM but will also remove trace elements that are better left in the seawater. However, because of the great value of the skimmer this is disregarded. If the aquarist does routine seawater changes then the new seawater will introduce trace elements.

When the dark and smelly effluent that collects in the skimmer cup has been seen, it becomes obvious why they are such an asset.

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Tags: Aquarium Maintenance, Aquarium Water, Care, Equipment, Protein Skimmer, Water Quality

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

Maintain That Skimmer

The protein skimmer is a device that is essential to the maintenance of high quality seawater in nearly all systems. There is a system that claims to not need a skimmer, but aquarists often run one anyway. Using a protein skimmer is particularly useful to experienced aquarists and beginners alike.

The skimmer when purchased, whether a hang-on or stand alone model, should be sized at around twice the net gallonage of the system. This is because manufacturers can be a little enthusiastic about skimmer capabilities, and it also takes into account, up to a point, the less efficient skimmers on the market.

Any device is only as good as the necessary maintenance it receives. The skimmer is no exception.

There are (I assume) not that many air driven skimmers left in use. If the skimmer is air driven, then it is important to ensure that maximum air is being delivered properly. This is done by ensuring that the air pump is operating at full efficiency, without clogged air filters or damaged diaphragms. The bubbles coming from the air ’stone’ should be very large in number and very small in size. If they are not, change the ‘stone’ for a new one. If this doesn’t make any difference check the pump for problems as above.

The skimmer is more than likely to be a [tag-tec]venturi[/tag-tec] model nowadays. These come in different guises that are essentially the same - flowing water from a pump passes an intake where air is taken in. The air is pounded into small bubbles by the pump impellor or a variation of this. Again, the bubbles should be very numerous and very small, If they are not, check the air intake (venturi) as these have a tendency to block. Switching the unit off can often clear them by allowing the blockage to dissolve. If this doesn’t work, check the air line to the venturi is clear. Always adhere to the manufacturer’s maintenance instructions.

There are other skimmers which are less common.

All skimmers should have the bubble chamber packed with bubbles. This is often evident by the colour - the chamber appears close to white.

A very important maintenance task with a skimmer is cleaning. Over time, the period depending on the level of [tag-ice]dissolved organics[/tag-ice] in the seawater, the cup will fill. This should be emptied and cleaned. Whether the cup is full or not, the aquarist should check the condition of the effluent throat (the part where the bubbles rise up towards the cup). This is because a layer of scum builds up here, and the efficiency of the skimmer is directly affected by it. Clean it off and maintain efficiency.

A skimmer does not always perform at full efficiency when new. This is because of the manufacturing process and the plastic. It will soon settle down, however. The same thing could happen for a shorter period when the skimmer has been cleaned.

The great majority of aquarists should have a skimmer and run it continuously. It is a direct contribution to the health of the aquarium.

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

Is Yours Scummy?

Sounds as though I’m getting too personal! I’m not, it is definitely to do with the fish only aquarium or reef aquarium. It is equally relevant to both. Another possible target of such a question is the protein skimmer. That could be involved, but not entirely.What I’m actually on about is the aquarium water surface. The best condition for the water surface is clear and clean. This is because this area is a major point for gas exchange.

A scummy water surface can be seen best by looking upwards at it through the front viewing glass. The scum is usually a mixture of bubbles, very small bits of organic matter or general dirt, and has an overall oily appearance. If it is there it most certainly is not wanted.

What causes this surface pollution? First of all, the seawater may hold an excess of dissolved organics. These organics can be generated by overfeeding, excess fish, lack of water changes etc. The organics tend to accumulate generally in the top ½” or so below the surface (this does not take account of powerful water circulation features, but is correct overall). Organics are attracted to an air water interface which is why this occurs. This is how the protein skimmer functions, by presenting a large air/water interface for the organics to ’stick’ to. This air/water interface is, of course, the mass of tiny bubbles within the skimmer chamber.

One method of removing the surface pollution is to use strong absorbent paper sheets, which are laid on the surface gently and then gently removed. Much of the pollution can be removed this way. It is not particularly easy, however, and doesn’t treat the cause, so it is likely that the scum will reappear.

So, if scum has appeared on the water surface, the first thing to check is the protein skimmer. Is it functioning correctly? Is it cleaned regularly (scum accumulation in the skimmer neck will impair the rise of foam towards the collection cup)? Has it the capacity to deal with the water volume? As a general guideline, the skimmer should be rated around twice the capacity of the aquarium system net gallonage.

Having checked this, the next check is feeding. Overfeeding can increase organics (and nitrate/phosphate) so the answer is - don’t overfeed.

Water changes should be completed on a routine regular basis. Not only will this reduce organics, it should reduce nitrate/phosphate to an extent and go some way to replacing trace elements.

Many aquarium systems nowadays will not suffer from surface scum. This is partly to do with vigorous water movement, but also because many systems use weirs or other overflows to deliver water to a sump below the display aquarium. These weirs and other overflows allow the water to flow out of the aquarium at the surface, and thus accumulating debris and organics go with it. The water when in the sump is available to a protein skimmer when organics are removed.

A clean water surface is essential. This is because, as already said, it is a major area for gas exchange. It is where oxygen is taken into the water. Oxygen rich aquarium water will deliver, other things being equal, healthy livestock.

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Tags: Aquarium Filtration, dissolved-organic-compunds, Equipment, Protein Skimmer, Water Quality

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.

Again and again it is said how important the quality of the seawater is, and how it is imperative that high quality is maintained. The protein skimmer is a device that acts directly on the seawater quality and should be present, particularly on the aquarium of an inexperienced aquarist.

The protein skimmer (let’s just call it a [tag-tec]skimmer[/tag-tec]) either hangs on the side or back of the aquarium, or is a standalone that sits alongside the sump. A pump, usually supplied, is sometimes within the skimmer body (hang-on) or is inside the sump (standalone). The pump sends water through the skimmer, and at the same time a venturi inlet (taking the venturi as an example) allows air to flow down and mix with the passing water. The pump impellor (there are various ways this is done) smashes the air into minute bubbles. These bubbles enter the skimmer chamber with the water.

As can be guessed, the skimmer removes ‘proteins’, or organic substances from the water. To rid the water of these organics an air/water interface is required. This interface is the bubble, or rather the many numbers of them in the chamber. Organic molecules are hydrophobic/hydrophilic. This simply means that part of the molecule repels water and some of it is water soluble. The molecules in the water react to the bubbles by their water repellent part attaching to a bubble. Many molecules can attach to a single bubble.

A good skimmer will have a chamber that appears white because of the very high number of bubbles in it. These bubbles should be very small. The skimmer should be rated for around twice the net capacity of the aquarium system. If the skimmer is working correctly, a dirty looking foam should rise up the neck of the skimmer and be collected in the cup, where the bubbles burst into a dark liquid. (Skimmers do not always collect much for a few days after they are new, or after they have been cleaned, or where a low amount of organics is present in the water.) This skimmate should be emptied from the cup regularly and the cup and neck kept clean. The scum deposits in the neck etc will reduce efficiency.

A large build up of organics in the seawater can result in problems for the livestock - in very bad examples even death.

Some more advanced aquarists actually have their skimmers on timers as they do not want them to run full time. This is to do with certain corals being able to use organics as a food source. This practice should not be undertaken by a novice aquarist, as it requires careful monitoring.

Some aquarists run what is called ’magic mud’ systems. This simply means that a special kind of ’mud’ bed is in the sump, and it is claimed that because of this a skimmer is not required. Some aquarists may well be skimmerless, but many others run a skimmer anyway as they feel insecure without one.

Is there a drawback to using a skimmer? Yes, there is. The removed substances will include trace elements, and these trace elements are required in the seawater. However, regular routine water changes, and even trace element dosing if thought necessary, will maintain the element presence.

A properly sized and maintained skimmer is invaluable. It is arguably the biggest asset, or at least one of them, to the aquarist in the search for high water quality.

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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 [tag-tec]dissolved organic matter[/tag-tec] 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