Can anyone tell me what this yellow stuff is please?

[Julian]

I've been trying to grow some HC via the dry start method, everything is growing well except for this patch of yellow mold/fungus at the bottom of the picture.

It's only growing at the front of the tank which is where the substrate is at it's lowest, most of the substrate is at least 2 cm above the water level, here it's only about 1 cm. Could this be the probable cause?

I have a 14w heating mat under the tank which keeps the temperature in the 24-28 region. My Hygrometer says humidity is at 90%.

I've already removed most of it by hand, I've just scooped out the yellow bits and thrown it in the bin. I also added more substrate in this part of the tank so that it sits higher above the water level.

If there's anything else you think I can do or know what causes it, any help would be much appreciated.

 

[Andy Thurston]

Just been looking into this and its 1 of a possible 900 species if yellow slime mould. Its caused by damp conditions and rotting leaves. In the garden you carefully remove all of it minimising disturbance so not to spread the spores, do not spray it as this just spreads the spores further. The only suggestion i could give in the aquarium would be spot dose with liquid carbon, taking care not to dose the plants but i havnt tried it and wouldnt know what damage, if any, it would do to the substrate or surrounding plants, so it would be a bit of an experiment.
A bit late now but removing any decaying material from your dsm could help prevent this happening

 

[Julian]

Just been looking into this and its 1 of a possible 900 species if yellow slime mould. Its caused by damp conditions and rotting leaves. In the garden you carefully remove all of it minimising disturbance so not to spread the spores, do not spray it as this just spreads the spores further. The only suggestion i could give in the aquarium would be spot dose with liquid carbon, taking care not to dose the plants but i havnt tried it and wouldnt know what damage, if any, it would do to the substrate or surrounding plants, so it would be a bit of an experiment.
A bit late now but removing any decaying material from your dsm could help prevent this happening

I've been reading up on yellow slime mould, I agree it seems to look more like a mould than anything else. Do you think there's a chance it could have anything to do with this?

Aqua Soil Amazonia, Initial Stage Maintenance ||| ADA Nature Aquarium - Aqua Design Amano Co., Ltd

"Aqua Soil-Amazonia was developed mainly for promoting the growth of aquatic plants effectively. Its black soil contains plenty of humic acid which helps the plants' healthy growth. However, humic acid has a characteristic for seeping into water and turning the water yellow under an alkaline environment. It is more likely seen during the initial set up period of a tank, when Amazonia's black soil contains a lot of humic acid."

The slime apparently will disappear on it's own, and as long as I keep disturbing it, it shouldn't spread. I've also turned off my heating mat, I'm hoping this will slow things down also.

 

[Andy Thurston]

Its possible and what youve done to try remedy is worth a try. Mold in the dry start sometimes appears for apparently no reason. In the recent dry start journals, any problems with mould have all been with ADA substrates, this purely based on my observations from what i've read in the last 6 months and may be wrong. If anybodys read about mouldy dry starts with other substrates please feel free to let me know