wasp

A few years ago the wisdom of the time was that a RDSB should have a footprint at least 1/2 the size of the main display. However just how that figure was arrived at I have no idea. I think Joe Blogg is right you would need to evaluate just what you are wanting to achieve, and where your tank is at now. For example if it was for nitrate reduction, but your tank was already pretty low, a not too big DSB may suffice. Getting phosphate out of sand. Phosphate actually binds onto calcium carbonate, if that's what your sand is, and is pretty hard to get off. An acid bath may dissolve it off, however most of the overseas people who manage their DSB's by changing out a section of sand periodically, chuck it & replace with new to avoid the risk. If phosphate levels are well under control in your tank you may be able to risk using some old sand, long as it can be exported faster than it can leach.

Thankyou both. Well mine should be fine then, only other thing, how long has yours been in that position Chimera? The whole time?

You're onto it Fishboi

Another question also, the top pic, shows some dead bits around the bottom of the coral. Did that stay dead, or did the coral regrow over it again?

I think Layton has one.

Can you give me an exact description of lighting over that pocillapora please. IE Watts, distance, etc. Also flow & whatever else you think is relevant. I have this one, been recently put at the top, straight under a 150 w MH. First few days it lost colour but now is coming back but is still pale. I'd like to get it a good rich colour.

Good advice I tend to rebel against expensive / high tech, but in this case, a refractometer is the way to go. Not that expensive either.

Kinda sound like you are doubting me again Layton. :lol: Check this Quote - "Swing Arm hydrometers (Figure 1). These types of hydrometers need no temperature correction, both by their own claim, and by some limited testing that I reported in a previous article. Whether accurate or not, the salinity values determined with such a hydrometer are fairly independent of temperature." I can elucidate further if you still don't understand.

Well kinda . Had a go at top down photography thismorning in the frag tank but it's super hard. either too much light, reflection, or no light. Anyhow ended up with this pic which is bad but thought I'd post it anyway. The other thing is I haven't looked at them for a few days & they have all bleached bar one which is nearly bleached. Still alive though so I'll move the light further away. Some of the white ones had been showing great colours, and the purple one had looked awesome if somewhat unnatural, although it too has whitened now. So - No flack please I know it's a nutrient high tank & a bad pic. At least I've got the gall to post it

Not tonight, I'll do it tommorrow.

Yes interesting about the lighting, couple of weeks ago I pruned some of the sps, and just to see what would happen I put the bits in the frag tank, right under a 150 watt MH about 6 inches above the water, on a rack only 2 inches below the surface, so they really getting blasted. Getting some colours that are SICK! This despite it being a high nutrient tank, or I assume it is there is some hair algae.

Wonder if your low ca and alk of the past, has been the cause of all the anguish the whole time?

In fact most swing arms do not need temperature compensation as long as they are the same temperature as the water being tested. Unlike floating hydrometers which do need temperature compensation, strange as that may seem. Also do not assume your floating hydrometer is calibrated at 25 degrees. Many floating hydrometers are calibrated at 15 degrees. But it is correct that swing arms are not good, in fact IMO they should not even be sold. However as a short term measure Beachy you could assume that your water was 1.028 as per Cookie Extreme, so just know that when you're swing arm says 1.021, it's really 1.028. Even this can change over time though, my own swing arm I used to have would gradually change over time.

Whoa!! Dude!!!! That is one of the most AWESOME things I have ever seen!! Can't even imagine how they worked that engine, or the rest of the engineering.

Good to hear, I knew it would come together in the end. To simple folks like me I just twiddle the knobs till the reactor is set about right, but for those who don't like dealing in anything "abstract" :lol: , or who enjoy mind numbing calculations :lol: , here is a reactor calculator. Not really necessary IMO, but interesting all the same. http://home.comcast.net/~jdieck1/reactor.html

Well that's interesting about the pods. I pulled a DSB to go BB, the tank did clean up over time, and all the pods disappeared. I just assumed it was normal for the pods to die when going BB. I'm wrong? Maybe some of you guys got more nutrients than you realised? As to the whose got sand or whatever question, my 3 current tanks are BB. The two that are not display tanks can stay BB, but if I could I would go sand in the display, unfortunately current is hard to get right in a small tank & at this stage there is too much in some areas to have sand.

Well that's some useful info Layton, the kind of thing I'm looking for. Of course, even Steve's opinion is still only one mans opinion, but nonetheless he gets good results, awesome results to be precise. That's what I've been thinking too, that a sandbed kept in such a way that nutrients don't get too high, but providing the benefits of sand.

500 Frags!!! WOW!!! Wonder how some of those non zeovit bare bottomed tanks in the south island compare. Since zeovit causes so many problems, and sand is so bad, I'm picking they would be producing at least double, 1000 + , seeing they don't have the same handicaps as you, Cookie.

Anything useful to say?

Produce some logical reasoning? Are you saying myself and others have not done that? Being polite, all I can say is you must be blind.

That's what I used to think. The confusion is caused by BB protagonists immediately equating a sand bed with a dirt laden badly managed DSB. I'm not proposing that. I'm thinking sand has pros and cons. If the cons can be managed & nutrient paramenters kept within acceptable limits, maybe it also benefits the tank in certain ways. To further explain, users of zeovit are meant to "pump" the zeovit rocks daily. When this is done, a cloud of bacterial mulm is released. Shortly thereafter, sps corals can be seen expanding their polyps to catch it. If I get lazy & don't pump them for a few days, corals visibly don't look as good & also go paler. I'm thinking this mulm may be pretty much the same as what can come out of a sandbed.

Shouldn't be. What's wrong is I put up an idea for discussion, keen to find answers, but the confrontational approach of some turns it into yet another I'm right you're wrong thing, as Caryl said, she was quite right. Then I get "challenged" to prove this, prove that, the obvious intent being to shoot down everything I say. I'm looking for answers, not claiming to be an expert.

I'll agree with that but only in theory. In reality, two identical tanks will not be achieved. You could set up two identical tanks, but I'll guarantee there will be differences. Layton knows that too. I used to be a BB believer too, and still believe BB is the best way for a clean tank. I'm starting to doubt though that clean is everything. Why? Because what I'm saying is that anecdotally, I'm seeing better corals in tanks with sand. Having been thoroughly brainwashed that this is not possible, it was hard to understand. In fact I still do not understand it. Which is why I am asking for answers. At the moment, I simply do not have the time to pay you a visit. However if you can manage to get over my way you are most welcome it will be great to put a face to the name, and you HAVE to do Craigs also, absolutely healthy corals in a tank with sand.