lduncan

The oxygen, and carbon demand can be a massive load on the system, much more than the fish and corals.

... and associate bacteria, detritus etc.. It can be significant.

Increase life? It's just more bioload the tank has to handle. Sure, but nutrient removal isn't one of them.

When I say "bulk" i'm talking about 1 or 2 kg. It's not as cheap as 2 part chemicals.

Well detritus and critters go hand in hand. If you've got a lot of critters, you've got a lot of detritus, which is not good for water quality. If you don't run macro algae then you don't have the problems associated with it. But the conventional idea of refugiums is that you have algae in them. Whichever way you look at it, I don't think macro algae is a good mechanism for achieving good water quality.

Macroalgae leakage / secretions. Turpines, other yellowing organics. Macroalgae is a great trap for detritus, which sits and rots releasing nutrients into the water. They don't particularly help in keeping the water clean.

I'm tracking down a bulk source of strontium if anyone is interested. Could take two or three weeks to get here though. Layton

Not necessarily in a detectable way. But they do.

If that's you're main motivation for setting up a refugium. Forget it. Get a bigger skimmer instead.

Nope don't use one. If your looking at setting one up to improve water quality, you're doing it for the wrong reason. Macro algaes degrade water quality.

Not sure how much effect bulbs have. But flow is the big one, and not letting detritus build up in areas of rock. This is the basic idea behind it: http://www.xs4all.nl/~buddendo/aquarium ... ld_eng.htm The thing is, is that they for the most part can take nitrogen gas which is dissolved in the water and use it. There is no way you can stop this nitrogen dissolving into the water from the atmosphere. They always have a large source of nitrogen, fish or no fish.

But you have absolutely no control over nitrogen availability when 80% of the atmosphere is made up of it. It is near impossible to make it limiting to most cyano. That's why the focus on phosphate. You can make phosphate low enough in proportion to nitrogen to stop it's growth. Redfield ratio stuff again. I wouldn't think it would be a problem, considering the quantities of bicarbonate in saltwater. Layton

That's normal. Strontium is depleted rapidly.

It won't help. The phosphate has to be in the water to work. The thing is that if it had been sitting on the rock for a while then the rock can absorb the nutrients. Then it takes time for bacteria to migrate this out of the rock again. But for this to happen, the rock surface has to be kept clear of detritus, and water has to be kept clean. I'm not suggesting ripping the tank apart. Just pay careful attention to the spots where this stuff is, and blow them out with a powerhead regularly, until they clear up. Layton

I wouldn't be so sure about that. While on the whole the rock may be good, if there has been detritus gather in particular spots of rock, then it can affect that particular part of the rock which explains why this stuff shows up in patches. Ultimately there is a phosphate source fuelling this. Find it and reduce it. Vodka / vinegar etc, may show more immediate effects but it doesn't necessarily get rid of the problem depending what it is.

vacuum isn't powerful enough, you need to blast it with a power head until no more detritus comes out, and then keep it clean and it should disappear given time. It won't disappear over night if it's nutrient source is in the rock.

Looking at the areas where the bubbles are. The problem will be a buildup of detritus trapped in and around the polyps, in the branching coralline on the stream cable, and the top of the stream. These are all places where detritus tends to build up. More than likely this is what's fuelling it. Don't worry about phosphate tests, they can only tell you how bad the water is. Bump up the flow in those areas and it will more than likely disappear. If the algae is soft it's a phosphate issue, if it's crunchy then it will be more of problem to erradicate.

Not to mention the phosphate they continually supply (unless you use a fully synthetic media) Phosphate is the problem, nitrate is not as large a problem as people think.

It's the gas heater, it pumps out kg's of CO2, and can significantly raise the CO2 levels in a room very quickly, which then lowers the pH of the water.

Industrial users can pay prices like that (or higher) on the spot market. The electricity industry is another thing which is seriously broken in NZ.

That's one of the features i like about it; the rock going right up to the surface.

Splitting hairs? No, It's just crap. Rock doesn't get old by the pores getting blocked over time by dead bacteria.

I like it. Anyone know what it's going to be stocked with? Stonies and just anthias would look great!

The rock doesn't get old because of dead bacteria blocking the pores.

It gets "old" by having it sitting in a dirty tank. If the tank is clean and stays clean, the rock will be clean and stay clean.