Need help with sand substrate?

[LuckyWanderer]

I have been trying to cycle a 5.5 gallon tank for close to 3 weeks now. Since day one I have had the sand that is currently in the tank go untouched due to cycling. I noticed today that there is some dark/grey sand just under the top layer. The original sand is a tan/white color. I'm not sure what this is but it's freaking me out! Please help!

 

[ZxC]

A picture is worth a thousand words

What's in the tank?
What has changed since you've started cycling?
How are you cycling?

 

[LuckyWanderer]

The only thing that I can think has changed is I have some green spot algae.

 

[LuckyWanderer]

Nothing is really in it at the moment. My cycling method is fishless, with fish food and I used stability.

 

[ZxC]

It doesn't look like anything too concerning so far, don't sweat it, just keep cycling as normal

 

[LuckyWanderer]

Could it turn into something bad though? And do you know what it is? This is my first time with sand and I heard it can produce hydrogen sulfide? Also, is this a good sign for the cycling process? I've had 4ppm ammonia for about a week now and it hasn't budged.

 

[ZxC]

I'm not sure what it is, I doubt its hydrogen sulfide though. Just keep ammonia at 4ppm and wait

 

[Angellove78]

"black" is not the sand itself but the accumulation of organics. This is normal and in fact wanted. Fish waste and other organic matter will settle on the substrate and work its way down into it. Bacteria then break down the organics into nutrients. Hope this helps understand better.

 

[LuckyWanderer]

So its a good thing? Does it mean anything for the cycle?

 

[Angellove78]

Yes, it's like gravel, it's just starting to collect in the sand like it would with gravel. That is basically your bb starting.

 

[LuckyWanderer]

So does this mean that my ammonia (4ppm) will start coming down?

 

[Angellove78]

So does this mean that my ammonia (4ppm) will start coming down?

It's still gonna take some time. But it's a start.

 

[LuckyWanderer]

I feel reinvigorated to wait for the cycle! Thanks so much!

 

[Wwidener]

+1 to Angel. I see what you're talking about and what Angel said is all I can think of. As long as your parameters are progressing properly, don't sweat it, for now. It could be a good thing.