Mould on substrate

kylith

Since getting my new tank I decided to switch from gravel to a plantable substrate. Money being what I is I read up on the Walstat method and decided to give it a try; substrate is John Innes compost capped with JBL Sansibar. It's going well; the plants are flying, the fish seem to be doing well (pretty sure the Apistos have either eggs or fry (I saw fry last week, but haven't seen them since and the female is keeping herself hidden again).

The only problems I'm having are a white mould on one side of the substrate and bubbles from the substrate. The mould doesn't seem to bother the fish at all, they don't try to eat it or anything. I've tried breaking it up but it's back again just as much in a couple of hours. Trying to vacuum it off just took a load of Sansibar with it. The bubbles, again, don't bother the fish (I've seen one of my tetras catch a small bubble and spit it out again, the fish is fine) I'm wondering if this is dreaded anaerobic bacteria, or just CO2 from bacteria in the soil or something.

Here's a photo: it's covering more substrate now, but I think it might be breaking up

Silverfish

I think that's similar to the slime/mould that appears on wood when it's first put in... might just be something in the substrate working it's way out.

I had nerites and MTS (for turning over the substrate) in my tank, so it wasn't there long enough for me to wonder about it.

Do you have any of those guys in the tank?

kylith

I have a pair of nerites but they stay mainly on the wood and plants at the minute, there's a couple of assassin's wandering around too.. I want some cories, but I was worried about getting them before the mould is gone in case it's harmful.

CruelCoin

Most composts have additives. could be something in it leaching out.

I'd give the whole thing a heavy siphon, followed by several large water changes.

kylith

If I try siphon it off it takes the capping sand with it and I'm left with naked substrate.

CruelCoin

kylith wrote: »

If I try siphon it off it takes the capping sand with it and I'm left with naked substrate.

What type of siphon are you using?

The siphon should have a wide nozzle and a narrow hose, like the one here:
http://img.ehowcdn.com/article-new/ehow/images/a04/9t/67/tank-siphon-vacuum-using-mouth-800x800.jpg

This allows you to sift through the sand and suck up any uneaten food (light) while the sand falls back down (heavy).

kylith

I'll order one of those, thanks!