Multicoloured Algae Problems - Help Please

[FishMonkey]

Hey all, about a week ago i noticed a small amount of what i think is black hair algae appearing on some of my ornaments in my tank, i actually went on holiday the next day so couldn't do anything about it, now i'm back it's definitely got worse and has started multiplying and i now have different colours of algae appearing on my gravel and need some help with what to do about it if possible?
 
Usual required info:
 
Tank size: 110L - 81 x 36 x 45 cm
pH: 7.6
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 40ppm
Hardness: Fairly Hard
Tank temp: 25c
Volume and Frequency of water changes: 25% Weekly
Chemical Additives or Media in your tank: Seachem Prime with water changes
Tank inhabitants: See my signature
Recent additions to your tank (living or decoration): None
Exposure to chemicals: None
Photo's:
 

 

 

 

 
Thanks for reading, any help greatly appreciated!

 

[DerpPH]

adding plants there can help cope with algae problems if you don't have excess lighting. how many hours do you light your tank and how are your params?

 

[FishMonkey]

My params are posted above, and i have 2 x 18w T8 Juwel Day-Lite bulbs which came standard with my tank, i have them on for about 4 hours per day, and the tank isn't in direct sunlight.
 
Do you think adding some malls balls could help then, or do you mean large plants?

 

[DerpPH]

My params are posted above, and i have 2 x 18w T8 Juwel Day-Lite bulbs which came standard with my tank, i have them on for about 4 hours per day, and the tank isn't in direct sunlight.
 
Do you think adding some malls balls could help then, or do you mean large plants?

I mean large plants like hygrophila. cabomba and other easy to grow plants
 
Your main reason for the algae is your spike in nitrate.

 

[FishMonkey]

My Nitrates have never dropped below that as my tap water measures the same, i have been in contact with my water company and they have advised that the legal limit for Jersey is 50ppm so the 40ppm that i have in my tap water is perfectly acceptable, obviously i argued this with them, but they showed me the legal stuff and sure enough, they are just below the limit.
 
I've got gravel in my tank and don't like the idea of having real plants in that, would want to change the tank completely if i was going to plant it, is there no way to fix this without planting my tank?

 

[DerpPH]

why not plant the tank? some plants can survive in normal gravel. well you could try those nifty algae removing chemicals if you want but they work for only a while then boom the algae is back which leads you to buy more of it

 

[FishMonkey]

I could do, but would want to change the gravel for black substrate and am not sure if i'm ready to start a proper planted tank, what i've been thinking is not easy (for a beginner like me) and think i'd need to go to a high-tech setup (i'm all or nothing really) and am not sure i can commit to that at the moment,
 
I did buy some API Prevent Algae when i first got my tank as it was recommended to me by my LFS (before i did any research) but i haven't used it yet as from what i've read on here, you should only use chemicals if absolutely necessary.