lduncan

It's not a war. It's how DSB's work! It's got absolutely nothing to do with BB methods. Layton

You'd be surprised the PM's I get, from people who can not be bothered posting in these threads based on the attitudes of some on this forum. What you call worthless theory, is actually based on experimental data and findings, some done in controlled aquaria. Layton

Went from 13 month old 20k's to new 10k's (both 400's). Dropped photo-period from 9 hrs to 4 hrs for a week when I did. Bleaching happened the first day after the change. All but the one coral recovered within a couple of weeks. Layton

Simple, because of the mis-information presented by others here. Problems, well, Off the top of my head Added a Deltec skimmer, which lead to rock shedding detritus, lead to problems keeping alkalinity up as bacteria activity was using it. Lost two corals to this, severely affected a few other corals. This caused a lot of problems. added new bulbs, caused bleaching, lost one coral to that. top centre glass brace snapped. return pump impeller blew to bits a few days ago, after 5 or six years running (and only two or three cleanings) Can't think of many others at the moment, there probably are some more though. BUT none of this has anything to do with how sand beds works. Layton

Where do I start with this one. Frankly, I don't care what methods you choose to run your tank. If you run BB you should know what it does and how it works. If you run SSB you should know what it does and how it works. If you run a DSB you should know what it does and how it works. What i'm doing is giving people the information so that they PERSONALLY can decide what is right for their tank. There is no need to ignore what these methods do, just because you don't like the sound of it. I'm not judging anyone based on the method they have chosen, but I won't let crap like "badness" in and "goodness" out stand, because it's just not how it works. I'm talking about using sand as a filtration method. You'll notice that the expert proponents of DSB system state that you DON'T ever disturb the sand bed. What you're talking about here is sand in a tank, not a filtration method, which is what i'm referring to. The reason why people clean their sand, is because of what sand beds by there very nature do. That is store things in the tank, which should be removed. If you keep the sand clean, then no problem. It's a big task but can be done. If you know what the sand bed does, then you'll see that doing this can also have other implications. Which is another reason why you should at least understand the basics of how the system you have chosen works. People have different ideas of "crashing". I call continual problem algae a crash, others might see that as part of setting up a tank. There are numerous examples of tanks where sand has caused issues, some by the experts, and many by private individuals. Layton

That's a bit vauge. That's why I asked the specific questions above. Can you answer those? Layton

Yip, mostly. How is it skimmed when it's in the sand at the bottom of the tank? Why would the bacteria leave the sand en-mass? They're there for a reason. This isn't going to stop phosphate pooling in the sand bed. They are also involved in the retention of phosphate and like phosphate, they accumulate in sediments. Well sulfate and sulfur is extremely important in many of the processes going on in sand beds. It's used by denitrifying bacteria to do their job, and, in conjunction with other bacteria, is also involved in iron's ability to bind and release phosphate. Layton

If the sources I've provided are wrong, what's goes on in the sand in your tank? Where does the nitrate go and how? What happens to phosphate? What happens to metals like iron, copper, manganese? What happens to sulfate? Layton

How?

Nothing vaugue about it. It's saying if you have a sediment, with oxygen gradients within it, you get storage of phosphate by the bacteria which reduce nitrate. And that release of this stored phosphate is triggered by a number of different events, ultimately causing suboxic boundary moving closer to the sediment / water boundary. Now, in a tank you have a sediment (sand bed) and you have bacteria. The question is, is for this process to NOT occur, you have to somehow stop the bacteria grabbing the phosphate. How do you do this? You have no control over it. One of the benefits of DSB's are that they reduce nitrate. If they are doing this, they are also storing phosphate, for later release. So, how does this NOT apply when you move the sand from the ocean into a glass box, where water volumes relative to sand area are much lower, and phosphate input per unit volume is much higher? Layton

Hey Pies, have you died before? You do know that people die at some point, don't you? Or do you think death doesn't apply to you because you've never actually died before? Layton

I wonder why that was? Maybe the sand doesn't convert all the "badness" into "goodness". Maybe it does behave the same as sand in nature does. The only difference is that it's in a glass box, with a lot less water to buffer any effects, and with a lot more input of phosphate. If you're interested. Walter Adey was a massive proponent of natural DSB type systems. It doesn't take much to find that even this self expert on such systems couldn't make them work different to what they do in nature. He has a string of public failures after his name. The Smithsonian, the GBR aquarium, and a few others, all setup, and some maintained by him. He still couldn't get the sand to stop cycling nutrients like it does in nature. His couldn't keep sps corals alive, and had serious algae problems. Layton

So would the price of captive bred fish. For example you can get captive bred dwarf angels, like Centropyge interruptus for a couple of thousand USD. Compared with US$500 wild caught (they generally only come from Japan). Clowns $70 vs. $30. http://www.rcthawaii.com/ Layton

It's a broad ranging process. It's involved in the eutrophication process, and is well quantified. It happens in the ocean, it happens in estuary environments, it even happen in freshwater lakes. Any reasons you can think of why it wouldn't work in an aquarium? These studies are generally (not always) done both in the field, as well as in the lab, using controlled aquariums. The controlled aquariums allow them to verify their findings in the field. Surly if a DSB is a natural form of filtration, it works just like in nature? Or is it better than nature? Layton

Cool time lapse of two corals facing off (22 MB quicktime) http://www.nzreefs.com/coralwar2.mov (May need a up to date version of quicktime, it uses H.264 compression.) Layton

Well, kalk should deal to the calcium and alkalinity in one. Having said that, if you have a large bacterial sink of carbon in the tank (like a DSB), alkalinity can be used at a faster rate than calcium. This is when you need to supplement with baking soda. Alternatively, if your evaporation rate is not high enough that kalk can't keep up with BOTH calcium and alkalinity, then you need to look at a two part system using calcium chloride and baking soda, to deal with calcium and alkalinity levels, or alternatively run a calcium reactor. Magnesium is a separate thing. It's tested for and adjusted using Magnesium Chloride. pH takes care of itself if alkalinity is in line (and atmospheric CO2 levels around the tank are normal) Layton

Ok, here goes: While stirring an established sandbed is one way to initiate the release cycle, it is only one of many. Temperature and pH are other ways. All that needs to happen is a decrease in oxygen levels near the water sediment interface. The process is driven by bacteria. The same bacteria which are responsible for the reduction of nitrate: From http://www.ozestuaries.org/indicators/w ... rients.jsp From http://aem.asm.org/cgi/content/full/66/12/5236

... and the truth is also that those same tanks have sand which cycle phosphate.

That's not true at all. People say this all the time (usually when they have an incomplete understanding of what's happening), and it's nothing but rubbish. Science is all about finding the truth. Layton

Sure, but that doesn't change what sand beds do, and how they work. Layton

I see you've chosen to disagree with establish scientific proof of what they do. That doesn't stop sand beds from doing what they have done, and will continue to do for years. Simply put, if they did what you say they do, then the world would be a VERY different place today. Layton

Well the fact is is that sediments cycle phosphate. Either you are correct and the "badness goes in, gets converted into goodness, and the cycle continues", OR the scientist who have established long ago that phosphate (the worst of the "badness") just gets stored and released, and doesn't come out as "goodness" are right. You decide. Layton

I see you conveniently deleted the question mark in your misquoting of what I wrote. It was NOT a statement, it was a question. Followed by another question. Layton

So how do you run a sand be well? Layton

So you have no idea? No specifics? Layton