Black Stuff On Rocks And Smelly Tank!

[xamy_valox]

Hi there, last night I had a panic as I thought my cory had a parasite (he may do I just can't figure it out) so I did a 50% water change today to help get rid of any nasties.
I went to scrub my rocks as they are starting to get moss growing on then which I don't like, when I turned the one rock over it was discoloured, with black bits on it. I tried to scrub it off but it wouldn't budge. And where it has been aat on the gravel the gravel has turned black too, why is this?
Also my filter really really stinks, but out of nowhere! I do water changes every week and last week it was fine, but this week as I've gone to squeeze them out there was a horrific smell coming from them!! I'm going to buy some new ones today and replace one at a time throughout the week so I don't disturb my levels (which are fine and have been other than last night ammonia was at 0.25 another reason for my large water change).
Anyone got any answers for what's going on? I have a 70 litre juwell Rekord 700.
Thanks xx

 

[Louiseness]

Sounds like the black stuff could be a bacteria growth, similar to the kind you get in deep sand. It stinks but it supposed to be pretty harmless to fish.

 

[Harlequins]

Its not uncommon to have smelly filter media,how often do you swish your media in used tank water?

You may do more harm than good by changing the sponges...

 

[xamy_valox]

I do it every other week. This stuff is so smelly that it literally made me heave, it was awful. I've never had it smell that bad, normally it smells of soil or damp grass, but this smelt like sewers and I couldn't get the smell of my arms/hands.
Shall I get rid of the rock with this black stuff on as it is only that one that seems to have been affected?
I've had these filter sponges in since February, are you sure they aren't due a change?
Thanks xx

Also Harlequins, I know you have replied in a few of my cory related posts, do you have any idea what might be happening to my poor Leucomela? He looks like his veins are sticking out, or like a worm type shape is under his skin on both sides. It's the same one that has turned more or less black, any ideas at all? I'm at a loss and really don't want to loose him =[

 

[xamy_valox]

Since taking out that rock yesterday the smell in my tank seems to have vanished!!
I have had a casualty tonight (an expected one really) and so will do a water change after work tomorrow but glad I don't have that horrific smell today, just hope it doesn't return!

 

[hanny93]

No idea what the smell might have been caused by, probably some kind of bacterial growth, possibly why your cory might have been going black, if he was affected by that bacteria, but you shouldnt ever need to change your filter sponges, they last years and years, should only need to change them when theyre falling to bits, and even then over the course of months rather than a week

 

[xamy_valox]

Really? See I know the manufacturer will always say you need to change them like every 5 months cus they want your money, but I did think I would be due a change.
I'll just keep swishing and squeezing them out then until they are falling apart then and save me some money!!
I do change the very top one quite often, it's a cotton wool like one that caches the main debris as it gets slushy and brown quite quickly and disintegrates.
Amy xx

 

[hanny93]

yes i change that one weekly in my external, or biweekly if i have a major tank overhaul, like when i put new black sand in, i changed it twice a week for two weeks then because all the bits from the sand were still floating round, even though i washed it!! it doesnt hold any (if at all) bacteria, so youre good to change it every week or more

 

[xamy_valox]

Cool! That will save me a bomb then! Thanks, still upset about my poor cory though =[ bless him, he hung on for so long aswell!

 

[Fyurae]

Do you have any inverts in your tank, or snails? Black spots like that can be caused by a bit of rotting organic material. Dead snails come to the forefront of my mind. I learned the hard way to be very careful not to crush dead snails. I did by accident once and paid for it with my lunch! It could also just be a spot where plant matter or extra food collects.

 

[xamy_valox]

I have been over run with little pesky snails, I pick and pick them out but the numbers never seem to deplete! I tried putting lettuce into the tank at night but I only had one lonely snail on it by morning. I have crushed some when I have been trying to pick them out, but surely something so small couldn't give off such a horrific smell?!
Got any other ideas as to how I can get ris of them?
As I say the smell seems to have disappeared for now, I an only imagine it was the rock and my poor cory suffered for it =[