Algae?

[batbeanz]

hi all.
i have a freshwater tank about 6-8 week old,
i put some tropical fish in two weeks ago and a week later they had all died.
i have noticed some patches of what look like rust on the plants and glass around and on the heater.
i have tested the water quality and it is all fine.
i also added a carbon filter for any fine particles.
i have some liquisil general tonic but not added any yet.
what could this brown patchy stuff be?
thanks

 

[jayjay]

brown algae .... but have you got any pics to make sure?

 

[nmonks]

It's almost certainly diatoms. Absolutely normal in new aquaria, and can be persitent in tanks with few or no plants. In tanks with lots of plant growth, diatoms usually go away by themselves.

By the way, carbon has nothing at all to do with removing fine particles. Read this article in the TFF FAQ Topics, Beginner Questions section. The best stuff for removing fine particles is plain old filter wool. It's cheap, and does the job very well. Clean or replace every few weeks.

The first fish in a new tank need to be very hardy, if you're not doing a fishless cycle. It's important not to add too many. If you have neutral, freshwater conditions I'd recommend going with something like guppies. In soft water, a blue gourami might be a better bet, while in hard or brackish water, a couple of black mollies could be used. If you don't want these fish long term, ask the store if you can return them once the tank is stable. Good stores should be okay with this. I know stores specialising in marine aquaria that "loan out" black mollies purely for maturing new aquaria.

Don't waste your money on anything called a "tonic" or "aquarium salt". These are simply devices for extracting money from hobbyists. The only tonic that means anything is a water change, and you only need salt for brackish or marine tanks, and then you want actual marine salt.

Cheers,

Neale

 

[batbeanz]

i did think it was something to do with the gravel as it was second hand, i did give it a rinse in hot water but is it possible that it could have been carrying anything?
thanks for the advise by the way.

 

[nmonks]

Unlikely. Second hand gravel can be a good idea, since it brings lots of nice bacteria for the filter. On the flip side, there's a chance that pathogens could be brought into the tank (though recent veterinary work seems to have killed the idea that whitespot at least lies "dormant" in gravel). Rinsing the gravel in hot water did of course kill off most of the bacteria, rather defeating the point of the exercise. But it's done now.

The algae will go away by itself if you plant the tank up nicely. If you don't, then algae will always be there, and you will need to use some mechnical means, like a scraper or sponge, to get rid of it. See my article on algae and the algae-eater myth elsewhere on the site.

Cheers,

Neale

i did think it was something to do with the gravel as it was second hand, i did give it a rinse in hot water but is it possible that it could have been carrying anything?