Caulerpa

Mention the word ‘algae’ to a marine aquarist and the aquarist’s face might turn white, before he or she spins round to look at their aquarium and ask, in a panicky voice, ‘Where?’

We are all aware of that concern: nuisance algae! The stuff that covers everything in long thin strands of green or covers with a thin sheet of dark red or black looking film. Nuisance algae can be combated or avoided in the first place. But this isn’t about nuisance algae.

This is about nice algae for the aquarium! In the marine world there are a lot of types of algae that could come under the word ‘nice.’ They are decorative and sort after. Aquarists who use live rock may have been fortunate to see some grow.

Of course there is one algae that is essential, and this is the single celled type called zooxanthellae, or symbiotic algae, which dwells in the flesh of corals.

The algae here is Caulerpa sp. This is green, though the shade of green can vary, and generally grows longish leaves (sometimes up to 12″) which have various ‘patterns.’ The algae spreads by putting out runners, from the top of which the leaves appear. Underneath are holdfasts, which look a little like roots. The roots are simply anchors, however, as the caulerpa feeds through the leaves. This macro algae is very useful to the marine aquarist for decorative and/or filtration purposes.

A great deal could be written but all that will be done is a general description of the main types and what they could be used for.

The first and probably best known is Caulerpa prolifera. The leaves are plain and have straight edges which taper to a point. The leaves are normally flat. Growth is fairly speedy.

Two more attractive types are Caulerpa mexicana and Caulerpa seratuloides. They both have leaves that look a little like bird feathers, with individual sections sprouting from the stalk sideways on both sides from bottom to tip. These types could show rapid growth.

A different appearance from the previous types is Caulerpa racemosa. It is often called grape caulerpa because of the appearance: the leaves are bunches of small grape-like growths attached to the stalks. This type is more slow growing and more difficult to cultivate successfully.

What can be done with caulerpa? For decorative purposes it would of course be in the display aquarium, where it can look very attractive. However, the aquarist must be sure it doesn’t outgrow its welcome as some can spread rapidly. I had some Caulerpa mexicana in a previous aquarium and it was certainly attractive, though I had to harvest it regularly to maintain control.

The other area that caulerpa is often found is in a sump. Aquarists grow it there so that it can act as a filter. As it is an algae, it uses the same nutrients that nuisance algae does, that is nitrate and phosphate. In doing so it robs any potential nuisance algae of food. Even if hobby test kits indicate zero (undetectable) for nitrate and phosphate, it could well be that there is a low presence. Planting a piece of caulerpa and watching to see if it grows is possibly an indicator. Obviously, algae in a display aquarium will also reduce nutrients.

As with all plants caulerpa needs light. Fluorescent tubes such as T5’s or metal halide bulbs should be fine, so growth in a display aquarium should not be a problem as far as this is concerned.

Caulerpa grown in a sump can be lit a little differently. A fluorescent light with reflector will suffice, the light is usually quite close to the seawater surface. There may be an advantage in using a tube that has a K (Kelvin) value that is lower than normal for a display aquarium, such as 6500K. Or a white marine type can be used, around 10000K. In addition there are two ways of timing the ‘light on’ period. First is to leave the light on all the time without any dark period, which doesn’t seem to have any detrimental effect on the caulerpa, and the second is to have the light on period when the display aquarium is in the light off period. The second option could assist with pH stability - pH could fall a little when the display is in the dark period, but with the caulerpa lit this is counteracted.

When planting in a display aquarium, try the type of choice and see if there is any success. If not, try another type. In the sump, it could be a good idea to plant more than one type and see which ’takes’ first.

Caulerpa should be harvested from time to time, always leaving plenty to continue growth. As the plant uses nutrients, removing the caulerpa in a controlled manner also exports nutrients.

The aquarist may find that the caulerpa in the display aquarium is disappearing. Have a look at algae loving fish such as surgeons and rabbit fish - they could be fat and very happy!

Important Note: Caulerpa in the aquarium is fine, decorative and useful. However, when harvesting, or simply removing caulerpa of any type it must not be thrown away into the sea. Caulerpa is invasive and can and is causing problems.

In some areas caulerpa is banned because of problems. Please check the position in your area before obtaining caulerpa.

For some information here is a link:

http://www.sccat.net/#the-caulerpa-information-center-1e86c5

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Tags: Algae, Aquarium Filtration, Aquarium Lighting, caulerpa, deep-sand-bed, refugium

Can Tonga Live Rock Provide Enough Filtration?

Live rock as has been said time and time again is a phenomenal filtration medium. There are various different types of live rock available all of which provide the required filtration to the aquarium if enough is placed into the aquarium.

There is one in particular however that in my opinion is more decorative and ’standard’ live rock.

Tonga rock

Tonga rock is different to other types of live rock due to the reason that it looks like branches of a tree. It can be an extremely decorative addition to a saltwater aquarium. Due to tonga rock being thinner and not boulder shaped like the majority of other live rock with the obvious exception of plating rock you have the ability to be able to create fantastic water movement around it.

In my opinion tonga rock is fantastic for SPS corals as you can provide a large amount of water movement and if carefully aquascaped can look amazing. This is not to say that you could not have a fish only aquarium or a soft coral aquarium with tonga rock as you would be able to. You would just have to bear in mind that you will need to create caves etc for the fish to hide in as well as creating ledges to place the soft corals on.

But what about the filtration - is tonga rock as good as other live rock.

Tonga rock does have good filtration capabilities however they are not as good as other live rock. This is mainly due to the size of the physical rock. To purchase enough tonga rock to faciliate the filtration requirement would make it very hard to aquascape.

So what do you do?

In my opinion it is quite simple. I personally would use the tonga rock for decorative purposes and then have an in tank deep sand bed as well. The deep sand bed would be the main aspect of the filtration but the tonga rock would do some as well albeit reduced. You do not need to have the deep sand bed in the display aquarium it could be in the sump in the cabinet. You would just need to make sure that the partiton designed for the deep sand bed was large enough.

One of my dream aquariums (we all have them don’t we) is to have a 3 foot cube tank (3*3*3). In this aquarium a deep sand bed would be placed and tonga rock used for decorative purposes as well as some plating rock to provide some hiding places/ledges. Lighting would be provided by metal halides, the water movement would be chaotic and my corals of choice would be SPS with a small amount of fish.

We can but dream can’t we?

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Tags: Aquarium Filter, Aquarium Filtration, Care, deep-sand-bed, live-rock, refugium

At What Times Should The Lighting Be On Above The Refugium

In the refugium we are attempting to grow macro algae. The reason for this is that as they grow they remove nutrients like nitrate and phosphate out of the water.

In a previous post I have discussed what type of lighting should be used so that you can get optimum algae growth plus I have also talked briefly about harvesting the algae from time to time.

One thing which I have not really touched upon is how long you should provide lighting for.

There are two methods available - one which I agree with and one which I don’t.

I shall cover the one that I don’t agree with first.

Option 1 - Provide Lighting Over a 24 Hour Period.

So why don’t I agree with this?

Basically it’s because it does not happen in nature. There are some aquarists who believe that providing lighting over a 24 hour period prevents algae crashes from happening. This is where all the algae suddenly dies and all the nutrients which are removed are released back into the aquarium.

To me this has never been proven. If you look at nature the algae beds in the sea are exposed to sunlight over a determined length of time. The same as provided for the corals. You would not leave your lights on for 24 hours to provide light for the corals so why do it for the algae.

I am firmly of the opinion that we should attempt to replicate nature wherever we can. It works in nature so why try to change it in our aquariums?

I also believe that the algae needs a rest!

There is another factor to this as well. This is that in darkness the micro organisms come out more and start to feed and reproduce. It has been noted by many aquarists that they have experienced a pod explosion when the lights are out for a length of time.

Option 2 - Provide Lighting Over A Shorter Period.

This is my preferred option.

I have covered some of the reasons above. i.e. lighting is not provided over a 24 hour period in nature so why do it in our aquariums and the factor of the little critters which we are providing refuge to.

So how long is a shorter period. Well it can be many things but the method I use is that the lights above the refugium turn on when the main lighting turns off above the display aquarium - i.e. the metal halide lighting. They stay on all night and turn off when the metal halides turn on the next day. This is sometimes called reverse sunlight lighting.

So why do I do it this way and not have them on at the same time as the metal halides?

Basically this is so that I do not experience a drop in pH over the nightime hours. The reason this happens is that when the lights are on photosynthesis occurs, carbon dioxide is used and oxygen given off into the aquarium and the pH rises or in this case remains stable.

Stability as we all know is a major factor we are all hoping to achieve.

If we had the refugium lights on at the same time as the main display aquarium when all the lights went off there is a possibility that the pH will drop.

So that’s why I prefer option 2 - it simply makes sense to me.

Another thing that I also do is occasionally turn off the lighting above the refugium for a couple of days. I have found that when I do this I get a lot more ‘critters’ in the refugium. The more ‘critters’ there are the happier I am!

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Tags: Aquarium Filtration, Aquarium Lighting, Equipment, macro-algae, marine-aquarium, refugium

What Lighting Should You Use Above The Refugium

A refugium can be made from many things in the aquarium but for the concept of this article we shall classify a refugium as an area which contains a sand covering and macro algae being grown.

This type of refugium allows for two things to be completed :

1. A safe refuge for for animals to populate without fear of predation.
2. Excess nutrients to be removed by the macro algae growing.

The refuge aspect is created automatically simply by not introducing fish or other animals with feed on the little ‘critters’ into the area, For the excess nutrients to be removed though the macro algae needs to grow and for that it needs light.

Can you just use any light though?

Not really.

As we are growing plantlife we need to use lighting which is designed for this purpose.

For reference the normal lighting we use above a [tag-tec]saltwater aquarium[/tag-tec] is between 10,000 kelvin and 20,000 kelvin so can we use that.

We could but that kelvin rating is not suited for plant growth - it is suited for corals. Corals require lighting which is in the blue to violet range of the spectrum. Although it would work the macro algae would probably grow slower than if you used lighting designed for aquarium plants. Macro algae (and the majority of aquarium plants) prefer lighting which is in the red to orange range of the lighting spectrum.

For this reason it is better to attempt to locate lighting which is between the 5,000 kelvin and 10,000 kelvin rating with the lower end being the preferred end.

The interesting aspect here is that you do not have to utilise lighting which has been designed for aquariums. It is the kelvin rating we are interested in and luckily for us there are loads of house based lamps in this area.

Simply pop along to your local household store and check out the lights, read the label and see what the kelvin rating it.

Of course if you do not want to do this then just go to your local fish shop and ask for a blub which is designed for aquarium plants.

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Tags: Aquarium Filtration, Aquarium Lighting, Equipment, macro-algae, refugium

DIY reef aquarium sumps

Sumps are being used more and more in the salt water aquarium hobby nowadays. The reason is that a lot of the required equipment can be hidden from view in the [tag-tec]aquarium sump[/tag-tec]. Equipment such as protein skimmers, heaters, calcium reactors etc.

A lot of people nowadays are also using sumps as a place to install either primary or additional filtration methods.

Examples of these are mud beds, deep sand beds and refugiums.

The trouble with installing a type of filtration in the sump is that accommodating this where equipment is also to be installed means that the sump needs to be modified in one way or another.

Aquarists are looking at creating [tag-ice]DIY reef aquarium sumps[/tag-ice] so that this can be performed, and with patience is easily accomplished.

To make DIY reef aquarium sumps you will first need to plan and even draw what you hope to accomplish. Once this is done you need to obtain a basic aquarium of the relevant size as well as some glass or acrylic.

To make the required partitions you will need to cut the glass or acrylic. If you do not feel comfortable with cutting glass then a glass merchant will do this for you. Remember to take accurate measurements with you. When taking the measurements ensure that you leave a small gap between the partitions and the inner side of the sump.

Once the glass or acrylic is cut make sure that the edges are a clean cut. If they are not then it will be harder to attach them.

Now is where your patience will be tested.

For the next step you will require some aquarium sealant. Using a sealant gun place a bead around where the partition will be and gently push the glass or acrylic into place. The sealant should push put from around the sides - don’t worry about this at the moment. Check all the edges to ensure that there is enough sealant in place - we don’t want any leaks.

When you are happy that there is enough sealant in place leave the sealant to cure. Once cured you can use a sharp blade to tidy up the edges. Very carefully cut the spill over away, taking care not to cut into the core bead. Of course you do not need to do this if you don’t want to - some aquarists leave it as it is. Personally I like to make it as tidy as possible.

Once all the partitions etc have been created, and the sealant is cured and tidied up, fill the sump with water and check that it does not leak. I would recommend filling one partition at a time and checking for leaks - of course it does depend upon your design.

If you plan your design and take your time then you should hopefully be ok. If you do not feel comfortable at first why not practice on some old glass first.

DIY reef aquarium sumps are not that hard to make but the complexity of the design depends upon what you hope to achieve.

Tags: deep-sand-bed, mud-bed, refugium