# Hydrogen Sulfide



## cbwmn (Dec 18, 2007)

Hello
I have some “mineralized” potting soil. 
I was thinking about starting an emersed planted tank using that soil with Schultz Aquatic soil as a cap. 
In the past I have tried using the mineralized soils with Tahitian moon sand as a cap and wound up with a lot of Hydrogen Sulfide bubbles coming from the substrate.
I’m thinking that the TMS was too compacted to allow the gas to escape.
I wound up throwing it all out.
I would only fill the water to about an inch above the plants and let them grow to emersed.
Does anyone think that will work?
If I do get Hydrogen Sulfide bubbles can I just use a probe to release the gas?
And will it eventually go away?

Thank you
Charles


----------



## Zapins (Jul 28, 2004)

Best thing for emersed setups is just regular old nutrient rich black topsoil or potting soil (the richer the soil the better). You don't need a cap on it since it won't be underwater.

The way I set mine up was in a plastic under-bed container from walmart (13$). Then I added 2 inches of water in the bottom and put plastic shoe boxes (also from walmart or homedepot for 99 cents) with holes cut in the bottom into the water and filled them with 4 inches of soil. So there is a large tub containing water, then smaller tubs within the large one filled with soil. This setup is covered and a CF light is on the top. The soil layer is 2 inches *above *the water line.

If you cover the soil with water then you will have algae problems, but if the water level is below the surface of the soil like in the setup I described then you won't have algae problems (except possibly cyanobacteria) and the plants get plenty of water because the soil becomes waterlogged.

I also haven't had hydrogen sulfide problems with my setup.


----------



## cbwmn (Dec 18, 2007)

Zap
Thanks for the reply, this is all new to me.
If your soil is above the water line, then how do the plants stay damp until they 
grow to the emergent state?
Do you just keep it covered to maintain the humidity?
TU
Charles


----------



## Zapins (Jul 28, 2004)

Yes, just keep the tub covered with the plastic lid. 

As for the soil being wet enough: soil is like a sponge, it will soak up water far above the water level. There won't be pools of liquid on top, but it will be totally waterlogged and perfect for emersed plants. 

If you think about it, plants like HC and glosso can't grow very tall, so when they grow emersed in the wild they grow on river banks that are up and out of the water, though the soil is plenty damp for them.


----------



## SCMurphy (Jan 28, 2004)

If you are seeing hydrogen sulfide bubbles (can you smell rotten eggs) then the soil is not mineralized. If you are keeping the water line below the surface of the potting soil, you don't know if you are making hydrogen sulfide unless you are digging down into the substrate to check.


----------



## cbwmn (Dec 18, 2007)

SCMurphy said:


> If you are seeing hydrogen sulfide bubbles (can you smell rotten eggs) then the soil is not mineralized. If you are keeping the water line below the surface of the potting soil, you don't know if you are making hydrogen sulfide unless you are digging down into the substrate to check.


Quote:In the past I have tried using the mineralized soils with Tahitian moon sand as a cap and wound up with a lot of Hydrogen Sulfide bubbles coming from the substrate.
I'm thinking that the TMS was too compacted to allow the gas to escape.End quote

Sean
I just started an emersed trial.. I did not say that Hydrogen Sulfide was coming out of the substrate.
When I did try it, it was a planted 24 gallon aquarium with water well over the substrate.
The soil IS mineralized, it feels like sand.
Charles


----------



## cbwmn (Dec 18, 2007)

Zap

I'm going with your method.
Do you add ferts to the water?
Also, I was thinking about adding DIY CO2
to the water. But I'm not sure the CO2 would be able to get to the plants after the water is soaked into the soil.
BAD IDEA?
Charles


----------



## Zapins (Jul 28, 2004)

Nope, I don't add any fertilizers. I got the richest most nutrient filled soil I could find at home depot. Use compost soil, or black topsoil.

The soil will keep plants growing for years and you won't have to worry about hydrogen sulfide as long as the water level is below the soil surface level.

I tried adding CO2 (from a pressure system) to the emersed setup, but it didn't seem to make a difference. The CO2 level in the air is quite high, 385 ppm on average, versus underwater with 2-30 ppm. Your plants will grow plenty fast enough without CO2. This is part of the reason you want the plants above the water level and exposed to the atmosphere, not underwater - they gain 10x more CO2 from the air than the water.


----------

