Algal Bloom? Fish Tank Problem.

[Daij]

I have a brand new 4ft freshwater tropical community tank. It is a replacement for a tank that split. The new tank is in exactly the same position that the old one was - I never experienced any problems with the old one at all - until it split of course. The old tank was in place for more than twenty years.
When i set up the new tank, I noticed that after a few days the usual 'cloudiness' that you experience after a water change was not going away - in fact it was getting worse. I changed the water again and the cloudiness appeared immediately, the water change made no difference. The cloudiness was a greeny/ browny haze hanging in the tank. I changed the water daily for a fortnight and this greeny/browny haze persisted so I emptied the tank and bought another load of new gravel and the problem has come back. I am thinking that if it was a 'daylight' issue, why didn't I have problems in the twenty odd years that the old tank was in the same place?
I have been emptying the tank, cleaning the gravel weekly since Nov 2012 and the stuff keeps coming back - I'm changing a third of the tank water daily.
I have kept fish for 35 years and experienced some algal issues over the years but I have never seen anything like this before and am at a loss to explain it.
I think they call it an algal bloom, but I can't be sure. None of the algae control products on sale are touching it. The only constant thing about this tank is the fish - it couldn't be those surely? It just doesn't make any sense. Any ideas?

[wildwood]

Algae blooms are common in newly setup tanks. I guarantee a UV filter will clean it up. Washing the gravel only makes it worse as you've probably washed away the stabilising bacteria and the tank has to be re-cycled. Once the tank has cycled it will be easier to control the algae biologically. Live plants help to keep the algae down as they compete for the nutrients.

[hammerman]

Let the algal bloom take it's course. It will eventually run out of nutrients and clear. All the time you're adding fresh tap water, you're feeding the algea with the nitrates and phosphates that come in tap water.