Nobody in MLSSA to the best of my knowledge has grown macro algae in an aquarium virtually from scratch. What usually happens is that large amounts are collected, placed in the aquarium where they slowly decay, possibly after a period of some growth, with the tips going white.
This does not have to be the case. I believe I am on the verge of a breakthrough in this area and currently have Caulerpa, that had completely died in the aquarium, re-growing from stalks with a rich deep green colour. The growth I have is now about 75mm long and about 20 to 30 stalks have started growing. The tank water is crystal clear to an extent never seen before.
One of the major problems preventing the growth of macro algae is the growth of filamentous or "hair" algae which smothers macro alga. It appears that it was not until around 1986 that the major cause of this was discovered - high phosphorous concentrations in the aquarium. Now phosphorous is an essential element for the growth of all algae, but higher concentrations favour the growth of filamentous algae. Phosphorous concentrations should not exceed .05ml/L (loosely ppm, parts per million). My tank measured 2.5 mg/L, 50 times more concentrated!
The same applies to nitrates. Nitrates are relatively easily removed from aquaria but phosphorous is not so easy. Even so, my bet is that most aquariums of members harbour high concentrations of both nitrate and phosphate. Nitrate concentrations should not exceed around 3mg/L. Jean Cannon notes that the optimum ratio of P:N for macro algal growth is around 17:1.
One method of ridding tropical aquaria of phosphate is to buy expensive, non-rechargeable chemicals such as Seachem's PhosGuard from the aquarium shop and running water through them. This could cost several hundred dollars a year for large aquariums and is out of the question for most people. I was determined to find a simple, cheap method for such removal.
Having read many articles I was none the wiser. One substance often mentioned in tropical aquaria literature is Kalkwasser or Lime water, (CaOH). This, however, was mentioned as a method if increasing calcium in the water which is good for calcium rich corals, and is also good for maintaining Ph. At first I ignored this chemical.
I searched high and low and eventually found that phosphorous is now being removed from sewage effluent by a chemical method. Ferrous Sulphate or Aluminium Sulphate is added to the water at a rate of 0.4 mol Fe/ mol P. Not knowing the effect of Aluminium on fish I decided to try this method in the aquarium using Ferrous Sulphate.
I purchased a 1Kg bag of Sulphate of Iron from Bunnings Garden Centre. It is a fertilizer and iron soil en-richer. It is only 30% pure but I thought it was worth a try. I mixed up a solution of 2mg/L and let it settle. I was left with a clear solute of FeSO4. I calculated the correct amount of solute to add to remove all the measured phosphorous in my aquarium. It was 160ml.
It was do or die. I put it in the aquarium!
To my excitement next morning, my aquarium was crystal, crystal clear and the phosphate level had dropped by half. The following morning it had halved again. My sea urchin had come out and my remaining starfish got its colour back. I thought I had made a breakthrough!
However, such was not to be the case. My pH had dropped from 8.3 to 8.0. Ferrous sulphate was having an acidifying effect on my aquarium. I tried to correct it by adding Lime Water. Disaster next morning. The phosphate was up as high as it was before and the pH had not moved. The acidic sulphate was reacting with the alkaline CaOH. I was stymied.
"Limewater precipitates PO4 out of solution."
(http://www.athiel.com/lib/jaubert.txt)
Bingo! This was confirmed in another article where limewater precipitates phosphate over a period of five days. (Notes from the lab: Kalkwasser and Phosphate, http://www.nauticom.net/users/michaelh/notes.html).
I have yet to confirm this experimentally, but initial trials over two days appear to be confirming this. This being so, then we have solved the problem with phosphate without acidifying the tank.
In addition to this I have found further information that some aquarists "resort" to the use of ferric chloride, a very dark powder or crystals, to lower phosphate. This reaction takes place in a few hours and a sludge like precipitate, probably insoluble Ferric Phosphate, builds up on the bottom. Unlike Ferric Sulphate, Ferric Chloride has an alkaline reaction in the tank. I think limewater is safer.
Finally, watch your nitrates- but more of this later!
South Australian divers may have heard a little bit about the introduction of exotic species into Australian waters. It is said to be an increasing problem but we do not see much evidence of it in SA waters.
Fortunately, we have not yet seen anything of the large Northern Pacific Seastar which is decimating Tasmania's marine life. There is, however, one introduced species that seems to be rapidly establishing itself in our waters. It is the European Featherduster Worm (which is also known as the Sabellid Fan Worm). This worm could pose a major threat to our native marine life.
The European Featherduster Worm is a feral *Annelid worm which has recently been introduced into Australian waters. It is thought that it may have been carried into our country as hull fouling on ships from overseas. As a port, the area of Port Adelaide is highly susceptible to such introductions.
The worm has established itself in the Port River, the West Lakes system, Largs Bay jetty and around North Haven. They can also be seen at the West Lakes inlet off of Grange. Sightings have been reported from Nepean Bay, Kangaroo Island and Rapid Bay.
They are very similar to the Featherduster worms that have long been common in SA waters but they become more prolific once they are established. They grow quickly and reach their maximum length in about one year. They produce large numbers of eggs which develop into free-swimming larvae. They are also able to regenerate large portions of their bodies.
Concerned divers have thought of slashing them to pieces to reduce their numbers but, because of their regeneration abilities, it would make things worse. Their numbers would only increase at a greater rate.
*An Annelid worm is one that belongs to the phylum Annelida. Segmented marine worms, earthworms and leeches all belong to this phylum. Each of these, however, come from a different Class.
Featherduster worms are segmented worms which belong to the Class Polychaeta. ("Marine Invertebrates of Southern Australia - Part I" includes a chapter on Polychaete bristleworms (Chapter 6, p.228).) Polychaete comes from Greek for "many hair" and Annelida comes from Latin for "a ring".
The European Featherduster belongs to the Order Sabellida, the Family Sabellidae and its scientific name is Sabella spallanzanii.
The full classification of the European Featherduster then is as follows:-
Phylum Annelida
Class Polychaeta
Order Sabellida
Family Sabellidae
Genus Sabella
species spallanzanii
The Scuba Divers Federation of SA recently purchased a copy of "A Guide to the Introduced Marine Species in Australian Waters". It is a CRIMP handbook, published by the Centre for Research on Introduced Marine Pests at the CSIRO Marine Laboratories, Hobart, Tasmania.
The ring-folder guide has a page on Sabella spallanzanii featuring a photograph and a diagram. It describes much of the above in detail and says that the worm's known distribution includes Devonport, Tasmania, Port Phillip Bay, Victoria, Cockburn Sound, Fremantle, Bunbury Harbour and Albany Harbour, WA and Gulf St Vincent, SA. The guide also says that the worm poses a threat to scallop fisheries through bottom fouling.
An article in The Advertiser said that the European Featherduster Worm was discovered in Port Phillip Bay, Victoria in the mid-1980's. It decimated the scallop fishing industry there by forming large mats which smother other sea life and competes with them for food. A quarter of Port Phillip Bay is estimated to have the worm. The bay is said to be 2000 sq km so the worm is covering some 500 sq km of the bay.
Jenny Sampson wrote about the European Featherduster Worm in the May and June 1996 issues of the newsletter of the Coastal Waters Dive Club. Jenny's two-part article told of the worm's origin and described the worm in detail. It also described spawning, regeneration, preferred habitat, impact and potential for spreading by hull fouling. It also says that the worm has no known predators. The first part of the article included diagrams and explained much of the terminology used in the description part.
Steve Reynolds
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