It’ll grow low tech or high. However it does so much better in a high tech tank. Tried it in a couple tanks without co2 and it grew so slowly compared to with co2. Plus without the co2 it seemed to want to grow more vertically. The tank I have it in with plenty of co2, I can’t seem to get it to grow upwards, just keeps spreading.
first started growing it in substrate but decided to stick a few stems between rocks in my high tech tank and it just started creeping all over the rocks. It’s amazing how well the roots hold onto surface of the stone and looks pretty cool like that.
I read before that the side shoots tend to root a lot faster. However at least in my high tech tank I haven’t noticed much of a difference
If you want to limit side shoot growth, trim off the side shoots as they appear. It will force the plant to grow upwards. Once the plant gets too tall, just chop it off complete, and replant the top in the soil. You can leave the old stump behind or leave it in place. The stump will throw off new side shoots or it will decompose and turn into tasty fertilizer/mulm for your plants (or you can uproot and remove the old stump).
As a bonus, if you wait until the side shoots start growing roots, you can trim them off and plant them again to propagate new plants.