Help - Serious Algae Problems In My Tanks

[fishnovice]

I have two outside coldwater tanks on a stand with goldfish and golden rudd. Both are mature and cycled with no ammonia or nitrite problems. They are in the shade but still get a fair amount of light. The glass walls on both tanks were covered in green algae which I scraped off. However, I have rwo different problems now:
Bottom tank - The water has turned green and even after 2 big water changes shows no sign of improvement.
Top tank - Water has remained clear but I have just noticed that tank ornaments and plants are covered in black hairy algae, sort of like 4mm hairs which are difficult to scrape off. I took all fake plants out hoping the algae will die if allowed to dry off.
What is this black stuff and how do I get rid of it and stop it coming back?

 

[mike_980]

I have two outside coldwater tanks on a stand with goldfish and golden rudd. Both are mature and cycled with no ammonia or nitrite problems. They are in the shade but still get a fair amount of light. The glass walls on both tanks were covered in green algae which I scraped off. However, I have rwo different problems now:
Bottom tank - The water has turned green and even after 2 big water changes shows no sign of improvement.
Top tank - Water has remained clear but I have just noticed that tank ornaments and plants are covered in black hairy algae, sort of like 4mm hairs which are difficult to scrape off. I took all fake plants out hoping the algae will die if allowed to dry off.
What is this black stuff and how do I get rid of it and stop it coming back?

only thing you can do is to put a UV protecting sheet over the tanks most of the day while the weather is as hot as it's been, i work in a garden center which sells huge paddling pools and weve had alot back saying the in built filters dont work because the water turns green in about a day but it's only because of all the sun at the moment.