lduncan

So Pies, what happens in YOUR sand bed?

Can't you see that the same process that makes tanks which run dsb's successful, is the exact same one which is responsible for people whos tanks are plagued with algae and "mysterious" coral death. It the nutrient cycling in the sand bed which is responsible for BOTH of these. And it's something you have very limited control over. As for examples of tanks which prove that DSB's work; This tank here runs a DSB. Does this picture prove that DSB's don't work? Layton

It's cyclic. When the suboxic layer comes closer to the surface it reaches a point where bacteria dieoff reducing oxygen demand allowing it to re-oxygenate again and the storage release cycle continues. A number of other elements, such as iron and sulfur are involved in the binding and release of phosphorous in sediment too. It's an extremely well recognised cycle. Just not by some of the "experts" in this hobby however. Layton

UV does more than just kill stuff http://www.fnzas.org.nz/fishroom/uv-why ... 10335.html

Crabs and other critters produce waste too. So all they end up doing is removing a tiny bit, and transforming the rest into another form of crap. And what happens when they die? It all gets dumped back into the sand bed anyway. The sea also cycles phosphate in the same way sand beds in our tank do; storage, followed by release. It's the source of photo nutrients in upwellings from the sea floor. Of course there is a lot of water in the ocean, and not a lot of sediment. The only way to fully deal with waste in the sand bed is to physically remove it, by vacuuming or other similar means.

Then as the bed fills up, accumulating phosphate as it goes, the sub oxic layer move closer and closer to the surface of the bed, and it starts to leak phosphate back into the water column. But of course before this happens, it plays havoc with the rock. The rock absorbs the crap it's sitting in, that's were you can get algae problems with seemingly perfect water parameters, and mysterious sps coral deaths, caused by boring algaes. Layton

You forget that if the sandbed is doing that, then it MUST be storing phosphate. It can't do it without storing phosphate. Layton

I think the hobby is too small to annoy your customers over a trivial things like this. You could lose a lot of business over one or two hundred dollars. I know what I'd be doing, If I owned the business. There are plenty of sources of livestock in ChCh, and beyond. Layton

I didn't say it was. I said these were two reasons why I recommend starting with a 4 foot minimum tank size. Layton

Yip 100 litres is very small. It is the most likely cause of the blue tang getting whitespot. That sort of confined space for a tang like that is putting it under continual stress, making it more susceptible to disease. Also, water quality is harder to control in a tank that small, which adds to the problem. These are two of the main reasons why I, and others on this board, recommend a minimum tank size of 4 foot for people starting out in the hobby. It gives flexibility in the choice of livestock you can keep, and is large enough to make keeping stable water parameters and easier job. My advice: get a larger tank, or sell the tang. It really isn't suitable for a tank that size. Layton

Baking soda (Sodium Hydrogen Carbonate) does alkalinity, and therefore effects pH. Initially it can lower it, as carbonate / hydrogen carbonate equilibrium is established, and CO2 is released. This effect is only temporary. Layton

$180 a month on the tank alone. Layton

Maybe from "critters" and algae perspective, but from corals perspective it's more like a septic tank. Layton

...equivalent to the suns intensity at 5-10 meters below the surface on the reef.

Yip, the stress here is more than likely a blue tang being in a confined space. Layton

I don't think that is entirely correct. Lighting tests have shown that many 250Watt 10k halides put out close to the PAR found on the reef at midday cloudless sky at 5 to 10 meters below the surface. Layton

It is amazing to see the processes which go on in the tank (which are happening whether there is sand or not) when you remove the sand. The difference when there is sand there, is all that crud which gets trapped in the sand is absorbed back up into the rock which is sitting in the sand, only to be shed from the rock again by bacteria, that is when algae can get to it and take hold on the rock. It's like a convection process. Layton

The superman danae is bluish purple base with brick red polyps. I had one, until the monti eating nudibranchs killed it.

I have one similar which was about as brown a coral can get when I bought it, now it's turning a solid purple.

There is the problem. It will more than likely continue to have problems with disease while it is in a confined space. These fish need room. If they don't have it, they will get disease, even with good water quality. Layton

Don't worry Fay, the Amazon forest get vital nutrients, like phosphate, from the Saharan Dust events. They've been happening for years. Layton

Anyone watching Nat Geo at the moment, there is a program talking about Saharan dust, and the high iron content in it causing problems in Caribbean reefs with coral disease. Layton

Dallas / Maxium's free sample service is pretty efficient. You can get the iButton through that (worth US$25 in itself), but you still need the serial port adaptor and accessories. Layton

iButton uses the 1-Wire protocol, and packages the device in a ruggedised case.

Easy, ditch the sand altogether. Problem solved.