Tank Gravel Turning Black

[DSE]

I have a 120ltr tank which is just over a year old. The tank gravel when purchased was a creamy colour, over the last month I have noticed that it is turning BLACK, is this algae or is something strange happening to my gravel ? Currently I 'vac' the gravel every 3 to 4 weeks.

Thanks guys,
Dave.

 

[Miss Wiggle]

it's possible it's one of three things imo

1 - algae - this takes many forms and you need to get to the bottom of why you have it to get rid of it really
2 - waste - i think your vaccing schedule is a little slack, try stepping it up to weekly and see what happens
3 - the dye from the gravel leeching into the water, thus returning it to it's natural colour, it's not unknown for this to happen

 

[DSE]

it's possible it's one of three things imo

1 - algae - this takes many forms and you need to get to the bottom of why you have it to get rid of it really
2 - waste - i think your vaccing schedule is a little slack, try stepping it up to weekly and see what happens
3 - the dye from the gravel leeching into the water, thus returning it to it's natural colour, it's not unknown for this to happen

Thanks for the very quick response )

Number 1, how do I know if it is algae or not, is there a definate indicator or way of finding out ?

Number 2 - I only have 6 fish in my 120 ltr tank with an external filter, do you think it could be waste ? I have been on holiday recently and I used one of those white 'holiday' blocks, could this have caused/added to it ?

Number 3 - the gravel I was supplied looks like little pebbles I dont think it has any dye on it.

Also, I have taken a sample of the black stuff out and placed it in a bowl. After about 12 hours the gravel had returned to its normal colour, spooky. It also smelled a little 'eggy', is this the smell of waste or algae ? I dont know if it was algae that 'died' and so the gravel returned to its normal colour or the waste had dried and not kept the black colouring.

Thanks again for your help, you are a star.

Dave.

 

[Miss Wiggle]

ewww that sounds wierd! can't give you any definate answers

if the gravel wasn't died that's one thing to exclude at least

yeah the food blocks probably haven't helped, they're really bad, basically made of plaster of paris, most community trops can go 2 weeks without food just for future reference. they could well have polluted the tank and eithe rdeposited waste in the gravel or put some nutrients in making some sort of algae develop.

i would do a really big water change and clean the substrate really thoroughly, then you should have removed any build up of waste and excess nutrients from the food block so you can rule that out.

there's loads of different types of algae, maybe someone in the planted section can help you to identify it.

if you get a pic for us that may aslo help

 

[DSE]

Do you remove your fish before doing a large water change with lots of gravel cleaning ? I have two algea eaters who hide most of the time which dont really like me moving there 'homes' around whilst I clean. Is it less stressful for the fish to move them to another tank whilst I clean or leave them in and be carefull ? I just dont like it when they throw a wobbly, panic and go nuts when I move their house.

Thanks again for your help

 

[Aphotic Phoenix]

The stress of being moved to a different tank would really rely on several factors:

1. How similar the water is in the new tank compared to the old tank
2. How good you are at quickly and safely netting your fish
3. The current conditions of your tank, and how different it will be when the fish are returned.

Do you do regular testing of your water parameters? Check your pH, Ammonia, Nitrite and Nitrate levels. If the tank is quite funky you may want to start with a series of smaller water changes cleaning only sections of the gravel each time to avoid shocking the fish.