Try the dry start method (DSM), it grows a lot faster. If the stems have 2-3 pairs of leaves on it then just cut them and plant each node seperatly, in no time at all they will send runners out. It is said that low light causes glosso to grow taller allowing it to reach closer to the higher light. Its actually to do with the C02 concentration, so allowing it to start emmersed (DSM) will grow quicker and you will have your mat in just a few weeks.
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