First I am not "tall hand"...
ÁÙ¦³ TETRA ªº±øª¬°òªÎ n«ç»ò¥Î§r
»¡©ú¤W»¡ ©ÕµÛ©³¨F ¥i¬O³o¼Ë ¤ô¤£·|´ý¿B¶Ü
You have to mix the °òªÎ with some ©³¨F to form the bottom layer of your substrate...about 1 inche deep...then cover it with 2 more inches of plain ©³¨F (without any °òªÎ) to form the upper layer. Gentlely fill the tank and don't disturb the °òªÎ.
But if your goal is to maintain a lower pH, you should use the ADA soil. Since your tank is only 27L it won't be too expensive to do that, compare to buying °òªÎ and ©³¨F
1¬õ 1ÂÅ ¿OºÞ could be ok for plants, depending on their spectrum. Can you provide more info on these tubes? (like their K ratings..etc)