Gravel or sand

[Frederick]

Hi all.... Having successfully beaten the CO2 problems I have had three attempts at growing Riccardia and Hemianthus "Cuba" in the tank front gravel with very little success I am wondering if this ia because I have gravel and not silver sand.The problem is that if I wish to put sand in the front only,the tank is very much planted. I would need to remove some gravel and replace with sand. How could I stop the gravel collapsing into the hole. I do not wish to empty the tank but I would be prepared to remove all the front gravel IF i can retain the gravel at the back.
Any siggestions will be most appreciated alternatevly suggestions as regards very low growing carpeting plants.
Please help...... Frederick

 

[AAB]

Can't you put some sort of plastic divider or something to stop existing subtract sliding? I was thinking something like a lid of a margarine tub while you are putting the sand in. Others may have a better solution.

 

[Kristoph91]

Garden dividers. They'll hold it in place http://www.diy.com/nav/garden/fencing-p ... m-10278271

Then make sure you do some planting along the part where gravel meets sand. Or even some small rocks as a border. Otherwise it'll mix.
Take a look at a few journals on here - they'll help you out. Lots of people are faced with the same problems!