Even more new residents this month and some very interesting occurances, Thomas S. Heo is comparing reefers and reefettes, and an article on alklinity, written by DBW, is featured.

Editorial

Welcome again to OZ REEF Press, hope you are finding this both informative and entertaining. Well, I suppose Tom's Bit really fits into that last category, don't you think? ;-) I am pleased to inform you that OZ REEF Marine Park is doing great. Everybody seems to be happy, fully expanding, growing rapidly, or cruising around happily. In the middle of the day, when both of the metal halides are on, it looks really incredible, making all the work worth while. In August I will be able to show it off to my peers, by hosting that months Marine Aquarium Society of Victoria's Meeting. It will be a good change to have others that know more about it looking at the tank, other than people just pointing and saying, "Hey look at that funny fish" ;-).

Once again this has been a very busy front, both within OZ REEF and here on the site. A lot of new residents have taken up OZ REEF Marine Park as their home since the last edition. The tank has so much more now to look at, and with the added fish there is more action when looking from a distance. A complete list is below, but the new residents include a clam, brittle star, starfish, blenny, chromis, and hermit crabs.

A bit of reef rearrangement was done early this month, and that ended up being much more work than anticipated. One end of the reef structure, the lefthand side, was just looking a little too tightly packed and just did not look right. So, one Saturday morning I finally decided to stop putting it off and got straight in and started pulling rocks out left, right and center. Now that was the easy bit ;-), putting them back in was another thing. In the end must have messed around with it for 3 hours or so, it is amazing on how moving one rock can really mess things up either in the way things look or by unbalancing another rock making it unstable. But eventually I got it all back together, and it was worth it. Now it is more open, and more space is available in which to place more corals.

The lighting canopy was also completed early this month, with motivation appearing from somewhere to do the couple of rather large jobs done. The front swinging door was built and this looks great. It it can be swung up, then proped, to feed and do some regular maintenence, and if required can be removed within 5 seconds so that full access can be gained to the top of the tank. It looks much better now, and will have some photos online in a couple of weeks. Additionally two ventilation fans were mounted on the lefthand end of the canopy, which involved using a jigsaw to cut two holes. These will help with cooling in the summer, and both of them will be placed on a thermostat such that they come one when the tank temperature becomes elevated. And while I had the canopy off the tank for that, two plugs and sockets were added to the lighting hood and canopy such that the lighting hood can be fully remove by just unpluging two four pin 240V plugs. That will make things so much more easy next time some major reef structure work is required, or access to the circulation pumps on top of the tank.

A new stowaway on the live rock has been discovered. The stowaway is a crab about 15mm across, red, and only appears out to feed at night. During the day you may be lucky to spot him, but it is very hard with the camoflage that he uses. The front of his shell, just behind the eyes is decorated with pieces of macro algae. These are just cut off the algae in the tank and somehow stuck onto his back. Initially it was thought that it may just be growing on top of the crab, much in the same way as the snails, but just after he molted there was a new camoflage up on his back. Not 100% sure what he eats, but his claws are not very large, and when he is seen feeding he just picks around on the rocks. As soon as I get the chance I will get a photograph of him and put it online. But if he is seen harassing any of the other residents then he will be moving out pronto.

Additionaly my fears have now been realised, about two mantis shrimps are within the Park Enclosure :-(. One was discovered while an anemone was being feed brine shrimp, he just jumped straight out and pulled in one of the shrimp. He then came back out for some more. He appears to be about 8mm long and a pale colour. Then while watching the tank during the day a brittle star disturbed another one out from underneth a rock. This is another one, being slightly larger and a brown colour. Now the fun begins, trying to workout how to catch them before they get too large and start to make a bit of a mess of the tank. Currently pull the rocks out is out of the question as both rocks I have seen them in are on the base of the reef structure. But I have an idea or two for some possible traps to catch them with, so I will have to build them and see if I can catch them.

One morning when checking out the Park I saw a most amazing sight, one of the small anemoes was trying to eat a neighbouring zoanthid!!!! Over the next couple of days he had about three or four tries, and it was really interesting to watch. But he never really succeeded as the zoanthid was way too long to fit within the anemones stomach, but he sure did try hard ;-). Eventually the zoanthid moved away, most likely moved by a passing hermit or cucumber. The zoanthid was only free living in the sand having broken off from another colony in the tank. Luckily a photograph was taken, and you can check it out in the Postcard Tour. It did not work out that well, but it gives a good idea of how amazing this is.

At the last meeting of the Marine Aquarium Soceity of Victoria I managed to find out a bit more information about the large aquarium that is going to be built in Melbourne on the banks of the Yarra river. Construction is going to start in about May of next year on stage one, and hopefully be completed by September, 1998. An interesting aside is the fact that another company is planning to also built a large aquarium in Williamstown, which is only 10 odd kilometers from the CBD of Melbourne where the original is to be built. A court case was held and the original planners lost out, so know there is going to be two aquariums here in Melbourne. I doubt that it is going to be as large as the original aquarium, but this will be great. Additionally the one in the CBD will be just across the river from the new casino, so this will really work in it favour with so many people visiting in the vacinity.

On the site side of things, you may want to check out the Postcard Tour if you have not lately. Last week 22 new photographs were added to those already online. And some of these came up quite well, especially the ones of the cucumbers. Note that all of the photos contained on this site, unless otherwise stated, are taken by myself using a 35mm SLR camera with a 35-70mm zoom lens and a 2X zoom attachement for some of the close ups. Check it out. The Residents Directory has also been expanded a bit, including some of the new fish. If you happen to have additional information about a species in the Directory, or the information provided is erroneous please send an email.

If you are an Australian reading this, then I would recommend that you go and checkout Nathan Cope's WebSite pronto and add you name to the Directory of Australian Marine Aquarists (DAMA). This way it is much easier to share knowledge here, and hopefully build up a network that will help to build the hobby up here. As a last note, the views expressed in Tom's bit is that of Tom Heo, not me ;-). I have no idea where he comes up with this stuff, but he just seesms to keep on doing it. 'til next month.
Catch ya, DBW.

Welcome OZ REEF's New Residents

Another big month for new residents of OZ REEF, the ones making the most impact would be the school of Chromis and the T. maxima clam. Pictures of most of these are already up on the Postcard Tour and in the Residents Directory if they are their yet. If not then you will have to wait a week or two while I get this next film developed and scanned in.

• 1 x Blenny, unsure of the scientific name or even a common name. Eats algae, picking it off the rocks.
• 10 x Chromis viridis, Green Chromis, these guys are really cool. Constantly schooling over the top of the reef structure, and change colour depending on the lighting angle.
• 1 x Fungia sp., Plate Coral, brown with bright green highlights. Appears that is starting to bud off a daughter colony.
• 1 x Favites sp., Brain Coral, brown with green hightlings.
• 1 x Thelenota ananas, Spiny Cucumber, yellow to green, a colour morph of the orange/black/white one added last month.
• 1 x Starfish, unsure of scientific name as of yet. White with red spots.
• 1 x Chiridota sp., Cucumber, this one is unusual as has no tube feet and crawls along the sand. Still ingests the fauna living in the sand.
• 1 x Porites sp. ?, unsure on this yet, may be be Montipora sp. Domed shaped with small polyps, around 3mm across. Light green coloured.
• 1 x Clavularia sp., Star Polyps, nice small colony, light brown with bright green oral discs.
• 1 x Brittle Star, Mauve and tan banded.
• 2 x Blastomussa wellsi ?, Brain Coral, unsure to start with for the id of this one, but this seems like the most likely. Each polyp has its own branch, brown with bright green oral disc
• 4 x Hermit Crabs, small guys, grey colouring.
• 1 x Tridacna maxima, Maxima Clam, wonderfully coloured clam. Purple mantle, bright blue lines along the edges, and slowly fades into a solid gold then stops at the center.

Resident of the Month

Dear Marther ReefKeeper

Dear Marther,

I have heard that corals and live rock collected within Australian waters cannot be exported. But also I have seen Australia live rock advertised for sale within America. Either way it seems to me that some law is been broken, either by exporting something illegally from another country, or lying to the customer about the origin of the item. Are my concerns justified?

From,
Concerned Reefer

Dear Concerned Reefer,

Your concerns are justified Concerned Reefer. It is currently illegal by law for invertebrates and live rock to be exported from Australia. Fish are allowed and can by exported with the appropriate licences. The industry, collectors and distributors, within Australia is currently in the process of trying to change these laws to allow exportation. Within about 3 months a proposal presented to the government will be considered. But until then if someone tries to sell invertibrates or live rock from Australia, this has been obtained illegally. Several vendors within the United States have been seen advertising Aussie live rock for sale, but I believe this may even be from Vanautu. I do not believe that this is much better, as the vendor is lying to the customer, as you stated, about the rock being from Australia. Anyway as a precaution, ask of the rock/invertabrates origins before purchase, and if you are unsure then please do not by it.

From,
Marther ReefKeeper

Tom's Bit

by Thomas S. Heo.

Reefers and Reeferettes

on Livestock

Hermit crabs
Reeferette: Oh, how cute, they are so cute, do you see how cute they are? They are so cute.
Reefer: Dude, they are so f-in' awesome look at that one, dude, he's a bad-ass, look at how he just grabs onto that little one and tries to beat the shit out of it YEAH, go boy, GO!

Astrea Snails
Reeferette: That is so cute how they clean the glass, back and forth, with their little raspy-thingies.
Reefer: Dude, looks like a big ol' nipple I'm getting excited.

Sea Cucumbers
Reeferette: EEEWWWWWWW!!!!! Not in MY tank!
Reefer: Huh huh huh, that's a turd I could be proud of let's just fill the tank with 'em! I wanna show my girlfriend and I'm gonna make her touch it.

Green Chromis'
Reeferette: Look at their colors, they're so pretty, and how they follow each other around the tank all the time they are so sweet and cute.
Reefer: Dude, look at how fast they can swim when I put them in with the Lionfish they're only $1, and so, disposable!.

Aggressive Fish
Reeferette: Bad boy, you keep doing that, and I'll take you out.
Reefer: YOU DA' THE MAN Y-O-U D-A' M-A-N!

Clams
Reeferette: Oh, they are sooooo pretty. I can't believe that something like that was made by Mother Nature I think I'm going to cry.
Reefer: Dude, makes me think of sex.

on Hardware

Pumps
Reeferette: I think I'm going to take the average of the recommended flow rates and then divide by 2 so, 6+10=16/2=8, so I think I'll shoot for 8 times the volume of the tank for circulation.
Reefer: Hmm, if 6 times the volume of the tank for circulation is good, then more must be better? I think I'll get 3 MAK-4's for my 50 gallon that should give me about 4000 gph circulating in the tank. MO' POWA', MO' POWA', MO' POWA'!

Skimmers
Reeferette: This skimmer requires no assembly I'm going to buy it.
Reefer: This skimmer comes in 10,000,000 pieces and doesn't have any instructions whatsoever there isn't even a picture of what it's supposed to look like on the box I'll take it!

All-in-one controllers
Reeferette: This will make my life so much easier, and will save me so much money in the long-run.
Reefer: New toy to show off to all my friends I'm going to hook it up to my computer and then have it page me each time the water temp. changes by 0.5^oF!.

on this list's author

Reeferette: He's such a pig. I think that he got lucky once with that other list, and now he thinks he can just churn 'em out this one's not even that funny but he sure does have a nice butt.
Reefer: Anyone who can wait 'til the last minute to write something is okay by me and he's got a nice butt.

Special Feature

by

Alkalinity

What is alkalinity?

Alkalinity is a measure of the pH buffering capacity of water. (In this case alkalinity is not used in the chemistry context, as alkalinity is typically used to indicate that the solution has a pH above 7.0, i.e. it is basic or alkaline). It indicates the concentration of carbonate (CO₃^2-), hydrogen bicarbonate (HCO₃^-), borate (BO₃^3-), sulphate (SO₄^2-), and hydroxide (OH^-) anions. The actually value is determined by the amount of free acid, hydrogen ions (H⁺), required to neuralise all of the above anions.

Why is alkalinity important?

Alkalinity is what provides the correct and stable pH for a reef aquarium, if maintained at sufficient levels. A correct and stable pH, i.e. nonfluctuating, is important for the health of an aquariums inhabitants. Many authors state that alkalinity is important as it is a measure of the ability to resist a drop in pH. This is true, but it is only half of the story. It is also a measure of the ability to resist an increase in the pH, i.e. the "buffering" of the water works in both directions. Some components of the alkalinity buffer system are also utilised by organisms, such as hard corals, and so have to be present in sufficent amounts for good health and growth. Additionally, the higher the alkalinity, the greater the ability of the system to absorb the addition of an acid or a base with only small change in the actual pH. Alkalinity levels of 3.0 to 6.0 meq/ml are recommended to keep a stable pH in a reef aquarium.

How does a buffer work?

A buffer is a series of chemical species in a solution that resists a change in pH when either a base, eg hydroxide ions (OH^-), or an acid, eg hydrogen ion (H⁺), are added to a solution. It does this by acting as a reservoir for H⁺, donating them to the solution when the concentration falls and taking them from the solution when the concentration rises. The buffering system involves a base and an acid, in relatively high concentrations, in equilibrium with each other. The base acts as a hydrogen ion absorber and the acid as a hydrogen donator. When this equilibrium is upset by the addition of H⁺ or OH^-, which in effect removes H⁺, then the acid and base alter their concentrations until equilibrium is again achieved. When this equilibrium is reattained the pH is close to the original pH.

It is possible to buffer a solution at any pH by the choice of an appropriate acid/base pair. For seawater and human blood the important buffering system involves carbonic acid (H₂CO₃), hydrogen bicarbonate (HCO₃^-), carbonate (CO₃^2-) and of course hydrogen (H⁺). The chemical reactions involved are as follows:

The more important reaction for the buffering system is number 2. In this reaction H₂CO₃ is acting as the acid and HCO₃^- as the base. If H⁺ is added to the system the HCO₃^- acts as a base and removes the excess hydrogen ions from solution by forming H₂CO₃. And visa versa will occur if H⁺ is removed from solution, then the H₂CO₃ dissociates, releasing more H⁺ into the solution. The pH is thus stabilised by the equilibrium between the acid and base, adding or removing H⁺. Reaction number 3 performs a similar function. From this it can be seem that the entire equilibrium system is rather complex, with the formation of one species effecting the equilibrium position of another reaction and therefore the concentration of the other species involved.

The pH of a buffered solution is determined by the ratio of the concentrations of the base and the acid species i.e. [Base]/[Acid]. Therefore as the concentration of the acid increases over that of the base, then the pH will fall and visa versa. This effect can be use to alter the pH of a solution within a certain range to what ever value is required. Although this is not that simple within a complex system of a reef aquarium. Luckily it is not required to worry about this, as if the alkalinity is maintained at sufficient levels then the pH tends to the natural value of 8.0-8.4.

As the ratio [Base]/[Acid] determines the pH, therefore want to minimise the change of this ratio upon the addition/removal of H⁺. The buffering capacity, i.e. the ability to absorb the addition/removal of H⁺ with only a small pH change, is determined by the magnitude of the acid and base concentrations. This is easily seen when considering the ratio [Base]/[Acid]; the larger the acid/base concentrations, the smaller the percentage change in these concentrations after the addition/loss of H⁺, resulting in a smaller change in the ratio. Therefore to get the best buffering capacity and maintain a stable pH then this ratio has to remain almost constant. This will occur when the the amount of H⁺ that is added/removed is small compared to the concentration of the buffer species. As a result, the higher the concentration of the acid/base buffering species the greater the buffering capacity of the solution. This is why if a high alkalinity level is used, then the aquarium has a more stable pH. It should also be noted that a solution is better able to resist pH changes in any direction if the ratio [Base]/[Acid] is one.

How can alkalinity be maintained?

Alkalinity has a natural tendency to decrease over time in an enclosed system. This is due to the production of acids as by-products of biological processes and the utilisation of some of the buffering species by organisms. In order to maintain the proper levels of alkalinity more anions have to be added to the system. The source of these anions are as follows:

The Atmosphere

Carbon dioxide from the atmosphere dissolves into the water and then reacts with water to form H₂CO₃ as shown in reaction 1 above.

Carbon Reactors

Works the same as for the atmosphere, just more can be introduced into the system by operating under elevated pressures without having to rely on slower diffusion from the air into the water.

Water Changes

These introduce the buffer species into the system with the new water, whether synthetic or natural.

Powdered Buffers

These are powders containing the important buffering anions such as CO₃^2-, HCO₃^- and other minor components, and are added periodically to elevate the alkalinity.

Calcium Reactors

These not only help maintain the calcium levels, but also the alkalinity. Dissolvess CO₂ into the water and, because of the lowered pH, the CO₃^2- associated with the calcium ions.

Bibliography:
Delbeek J.C., and Sprung J., The reef aquarium: a comprehensive guide to the identification and care of tropical marine invertebrates, vol. 1, Richordea:Coconut Grove, 1995.
Raven P.H., and Johnson G.B., Biology, 2^nd ed., Times Mirror/Morsby College:St. Louis, 1989.

You Wouldn't Believe It!

..... hydra, member of the cnidaria phylum and very similar to corals, can be turned inside out and within a short period of time the cells reorganise back into the original configuration.

Bereavement Notices

Chromis viridis
One of the initial school of 10 Chromis only lasted about 4 hours after being put into the OZ REEF. He swam around slowly, not able to control his movements properly, then sank to the bottom and that was it. Left him in there, so a brittle star had quite a meal that night. Also lost another one after they were in the Park for about 2 weeks. Underfeeding is suspected to be the cause of this one, as their stomachs are rather flat. Hopefully this is now being rectified, with flake feedings three times a day, and four times on the weekend. The chromis also get a bit of brine shrimp meant for the mandarin and banded goby.

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