Posted By Steve Bennett Please don't shoot the messenger here but I have been asked a question regarding Legionella. I currently work for a Local Authority and we have recently issued a corporate policy on Legionella. A question has come back regarding tropical fish tanks - OK, when you have stopped laughing please read on. 1. The water temperature is between 22C and 45C. 2. There is a build up of sediemnt. 3. The system contains materials which harbour or provide nutrients for bacterial growth. 4. There is condensation and evaporation. 5. The water is recirculated. The only thing missing is the volume of water. We have these tanks in various care centres so the population "at risk" is often aged and frail. My first reaction was one of "go away and don't be silly", (or words to that effect!). However, when you look at the criteria for Legionella to thrive the tropical fish tank is a good fit! Someone please put my mind to rest on this one and then I can move onto the next "dumb question"!

Posted By Andy Petrie Legionalla is transferred via airborne droplets (e.g. shower heads, mist from cooling towers, splashes from high pressure taps etc), I can't see how a fish tank would manage to do this. Unless you're residents are using them to fill up their water pistols of course!

Posted By fats van den raad Right then.. Just spoke to my "Legionella man" and he says that he thinks it is highly unlikely as the movement of the water is not vigorous enough (sorry andy, you were right after all) He also says that the recirculation of the water and the constant oxygenating will prevent the bug from being present in the fishtank. Apart from that, he has never heard in all his years of a case traced back to a fishtank. (He did offer though, that, if you were worried, he'd come and take some samples for analysis....... typical consultant!!!!!)

Posted By Steve Bennett I suppose if you was to drop a Consultant into a tropical fish tank full of Piranha the water movement would be quite "vigorous"! Just kidding, it's Friday and I just wanna go home! Thanks for the feedback guys. Much appreciated. Steve (a Consultant!).

Posted By Heather Aston Only if you've got fins.... (Friday afternoon again huh?) Heather

Posted By Jonathan Breeze Heather, You've obviously not met Jim yet then, he is in fact a Sunfish IRL with this most amazing pectoral fin!

Posted By Gilly Margrave I don't know about fins but I am definitely a little Gilly!

Posted By Merv Newman Friday ? Who said it was Friday already ? What am I doing here !

Posted By Jason Touraine I would suggest dosing the tank with bleach to be on the safe side.

Posted By Andy Petrie Raising the water temperature to 70 C would certainly solve the problem, however I would avoid the fish soup in the canteen for the next few days.

Posted By Ken Taylor Presumably the water is in a respirable form for the fish. I wonder whether they are at risk from Legionella? The main issue I had to address with fish tanks was the proximity of non RCD-protected electrical socket outlets.

Posted By Jonathan Breeze In which case Fats, you will also need to check for Salmonella as well. Especially if you intend keeping terrapins. Can't vouch for Legionella though - it's not my area.