Yes, nitrite and nitrate. Thank you for the link, very helpful.

Sophia, this is in a well lit room, but no direct light. I chose the spot for that reason. The brown algae I have is like slime and dissolves when touched. It's very easy to wipe off. Although, I have noticed the problem is getting worse as the weather gets better.

The ammonia spiked again this morning. I've just done a decent water change, cleaned as much as I could off. In doing so, I pulled the equipment apart to find that the entire filter system had become clogged, severely reducing flow. I cleared it all by cleaning in buckets of aquarium water. So much brown and black gunk it made me gag.

The flow is much much better and i've changed the pump set up to do the same. The bubble tube was thick with algae even inside. I've concentrated the airflow in one area rather than spread out which has really helped with flow.

I've taken out those particular plants as advised, and also removed any that appeared to be rotting. I found that the BBA has started coming back too.

I think i've found myself in a vicious circle. The algae is blocking everything, which is making more algae. Just need to break the cycle.

believe me it is the same algae that I have. My tanks are also not in direct sunlight but the room is well-lit.

The filter sponge gets quite muddy too, like it's full of silt and I have to rinse and squeeze it out every 4-6 weeks. I don't get it inside tubes or on the underside of leaves, only on the outside of leaves where the light arrives.

ok, you'll know more about this than I would. i'll keep the curtain closed on the opposite wall, as that's where the main source of light is. It may be getting more sunlight than I realise when I'm at work. Is it light or UV? I was thinking of having the windows treated.

GGGGRRRRRRR I just popped down to the LFS to have a looksee at better filtration options and price them up. I neglected to close the cabinet door and my german shepherd has eaten my entire store of fish food. About $80 worth. I was highly unimpressed, then walked into the kitchen to find she'd pulled out and ransacked the garbage.

I'm not doing well on the pet front today....

you are doing very well, your dog just had a good feed :slfg:

I don't know whether you'd call it light or UV or both. There is light that gets through thick net curtains, and through the frosted glass pane of the door. The tanks are well back from where you can see the lighted area hits the carpet but it's obviously still enough to get the algae going. I also note that these tanks have their lights on for about 2-3 hours a day only, from around 5pm, and they have 6500k bulbs. The other tank I have that doesn't get that algae has a 6500k bulb and a 14000k bulb and is in the same area but doesn't have a pane facing the light so much.

retro fit DG tinted windows would reduce light and a lot of UV, but will be an exspenive option, also kinda ugly if the rest of the windows are timber or SG

or put a curtain in the way.....

personaly I forget to pull them or open them, retro fitting stops that brain fart situation