What to do????

[Rod54]

[quote:0c7702d93c]Why? When under gravel filters and regular maintenance do the job just as well for less cost? The cost of that will have to be passed on to customers, increasing the already (sometimes) riduculous prices of fish.[/quote:0c7702d93c]

Why?

I imagine that if a shop is lossing 100's of fish at a time...then they would have to increase the sale price of remaining fish to cover the loss...or eventually go broke.
Shops are turning over significant numbers of fish
...so every now and then it is resonable to expect you are going to get some with disease.
Sure gravel filters and regular maintenance do the job of keeping the water clean...but it doesn't kill "the bugs"
Having ozone on a system kills whitespot and bacteria,etc so it helps reduce their impact on all fish stock in usually overcrowded tanks.
If you able to reduce the mortality of your stock you increase profits which pays for the cost of installation of the system...and once that is paid for the owner of the lfs has a more profitable business and less unhappy traders and customers...=GOOD BUSINESS!

[braddo]

Only problem with that is when you take the fish home they have not been subject to any of these nasties and home aquariums don't have ozone treated water and it increases the fishes chance of getting these diseases as their immune system has not had any kind of exposure to them. Found this from one place that used ozone treated water and lost more fish from them because their fish were from too clean of water. It is almost like putting a fish in a sterile bubble and the first bug that they get once they leave the bubble kills em. Just my 2 cents worth from my experinces.

[Rod54]

Fair enough Brad if they are born and raised in ozone treated water...but I'm assuming the fish in lfs are only there for a month at most.
I'd suggest their immune system isn't going to be changed by a month(or less) in clean water?
I wouldn't advocate it for home systems because of the reason you mentioned but lfs tend to have fish coming from all over the place and stocking levels are a lot higher than in most hobbyists tanks.