Algae Growing On My Algae?!

[Ryefish]

I was recently told that the brown 'dust' in my tank is algae and quite common for a new set-up (which mine is, just finished a cycle not too long ago).
My tank is a 30L BiOrb and the brown has formed around the top of the air tube in the centre of the tank but now there is green algae growing on the brown! and the air tube is getting rather gross. This green has only appeared this week, i havent noticed it before now and i spend quite a bit of time looking closely in the tank. The brown is around the base of the air tube as well and there is black stuff growing on a bit of the gravel too - i can't really see this properly though because of the shape of the tank

pictures:
brown and green on air tube, and gross tube (hard to get a pic of, its like tiny green hairs that move with the current)

the dust

the other stuff

lights are on for 8 hours a day, dosing Seachem Flourish twice a week, Iron twice a week (no idea when i am supposed to dose this) and Excel daily. There are four Galaxy Rasbora's living in there currently, and ammonia is reading a 0, and Nitrates at about 15 which they always are.

I know i can remove the air tube and just scrub off the brown, which i have done before and it just came back, and i have an army (well, 3) of baby Apple Snails arriving next week but is there anything else i can do to stop this? I am worried my tank will be over-run before i know it. Or, do i just have to bite the bullet and deal with it?

 

[ian]

are you dosing any liquid c02, i can't remember?

it looks a bit like diotoms and bba. If i was you i'd buy a bottle of easycarbo, a little bottle would last you ages.

 

[Ryefish]

the Flourish Excel is liquid carbon right? Im dosing the recommended dose every day

 

[ian]

sorry, i missed that one, yes its the same thing...how much are you dosing?

 

[Ryefish]

the recommended dose on the bottle. my maths isn't brilliant but i worked it out to be 0.75mls daily, and 3.75mls after a large water change. Ive been using a syringe to get the right dose. It says on the bottle in massive letters "DO NOT OVERDOSE" so i tried to make sure the dosage was correct lol

 

[ian]

you can od, it does affect certain plants when you od, vallis and crypts don't tend to do well. Your should be fine. Also certain inverts don't do well (or from what i have read). My shrimp don't seem to be fussed. I would up the dose to 1ml daily. You can also spot dose, so get your syringe and spray the effected area.

 

[Ryefish]

spot dosing could be done
i dont have any shrimp yet but plan on getting them in a few months once ive figured out how much of my student loan ive blown so far
ill up the dose and try spot dosing and see if it will shift it

thanks for the help

 

[SchottayB]

I used the same fert as you, and it says to dose PER WEEK... I don't see anywhere that says Per Day

 

[Ryefish]

these are from the Plant Pack: Fundamentals
SeaChem Flourish - 5ml per 250L (60g) once or twice per week
SeaChem Iron - 5ml per 200L (50g) as required (im dosing twice a week)
SeaChem Flourish Excel - initial use or after >40% water change use 5ml per 40L. Daily or every second day 5ml per 200L (50g)

i chose to dose daily not every second day

ETA: you made me really paranoid then