Substrate "bubbling"

[DiscusEden]

I've had the tank going for a bit over 6 months now I think, and have Red Sea Flora Base as the substrate, under pool filter sand - or at least it used to be, before I sucked most of the sand up the cleaning syphon hose & out onto the garden.

The question is this:
in recent weeks, I've seen bubbles coming up on occasion from the substrate. I've watched & it's not coming from the fish. I thought it might be rotting food, so have given it a thorough clean (sucking up more of the substrate), but if anything it's getting worse. It could still be neglect, 'cos of distraction by puppy recently, but I'd like to know & find out how to fix it please?

TIA guys! :D

[revkev]

Have a look under the substrate push some away if its black and stinks you will have to clean it all ( been there done that ) :roll:

[DiscusEden]

Thanks Revkev!

Don't know about the stinks, but some of it is black. What is it?

Is it an algae? 'Cos I've had a couple of patches of what looked like blu-green algae on the sand early on, before I got the lighting/ferts/plants better balanced, that I just sucked off with the hose - is this a similar thing?

If I just replaced the substrate with Ecocomplete would the same thing just happen again?

[ILLUSN]

sounds like your substrate bed has gone anerobic, any deep substrate will do it eventually once it starts to compact, alegedly having substrate heating keeps a slow current flowing through the substarte so this doesn't hapen, ive got a 5 inch thick bed of eco complete and moon sand in my display tank with substrate heating, so far so good after 5 months.

[DiscusEden]

Thanks Illusn,

Is it toxic? Do I need to do something about it immediately?

[ILLUSN]

it can be some anerobic microbs can produce hydrogensulfide which is VERY toxic(smells like rotten egg), if you can remove it and wash it do that, maybe add a bit (?5%) 3mm gravelto stop it compacting again

[revkev]

The bubbles are gas from the substrate bed that has gone anerobic the only way to fix it is replace it with new substrate eco-complete is a good choice and try a cable heater system if you want to.
I have had substrate heating cables for over 12 months in a 6 ft planted tank with no problems some people like them other don.t. :)

[DiscusEden]

OK thanks. No smell of rotten eggs, but it smells like an aquaruim shop - like it needs cleaning.

What I might do is just replace it with ecocomplete, if it needs to come out anyway. Does that need to be mixed with the gravel, or is it large enough as is?

[ILLUSN]

mine is pure eco for about 3.5-4 inches then moon sand for the rest. works well so far.

[DiscusEden]

Thanks guys! Um, sorry, but what's "moon sand"?

[scott bowler]

hey DE he might mean this stuff
http://www.aquariumsuppliesaustralia.com.au/store/cart.php?m=product_detail&p=2578

[ILLUSN]

Thanks Scott, thats the stuff

[DiscusEden]

You guys are just plain clever, thanks!