[Delphinus]

As the saying goes, in an investigation, once you have eliminated the impossible, whatever possibility remains, however improbable, must be the truth.

Deduction: something is feeding the green water, such that it doesn't die back (otherwise it would).

Hypothesis: it must be something in the water, in the rocks, in the sand, in the additives, or in the food. (What else can there be?) The glass itself? The plumbing? The hardware?

Personally, I do doubt that it's the water itself. But this can't be said with 100% certainty. It IS a suspect until we get to the bottom of this.

I'm also quite undecided what to suggest myself as far as the 100% water changes go (hence the suggestion, delete the message, suggest it again, delete it again, process). I guess I WOULD be tempted to try it, but I am worried that it may shock the tank inhabitants, espescially if a series of attempts is needed. So maybe for starters, it is the UV and the refugium ideas, give it a week or so. If the water changes are absolutely mandatory then a temporary housing of larger inhabitants may be in order. A 100% water change on a 90gallon tank has got to be the absolute most invasive thing. Where exactly does one mix and age 90 gallons of water? Usually this is done in the tank itself well before adding anything live. Can't take out 90g and mix new saltwater in situ, fresh saltwater is nasty caustic. So it would have to be, probably, something like three rubbermaid garbage containers. Whew, isn't Alan's wife going to love me for suggesting we put 3 of those in her living room for a couple of days! [img]smile.gif[/img]

We definitely need a quantitative measurement of something though. We need to establish what the NO3 and PO4 values are. If we can identify one of these are being out of whack, then we can try to attack that one parameter and once it's under control see what happens to the colour of the water. Until we know numbers, it really is just guesswork (we seem to be assuming phosphates are whacked, let's at least start by proving that theory correct.) Alan I can't come over tonight but maybe I can come over tomorrow or Friday sometime (daytime Friday preferred) and bring some of my testkits, let's see what we can't find out about this.

[ 17 July 2002, 15:30: Message edited by: delphinus ]