Another thing I have observed is that with cooler temperatures in the tank the root development is better, but the absorption of nutrients decreases. I have noticed this very clearly because the Kali AK, which had a couple of degrees more than its companions (I do not know why) has developed a much smaller root ball than the rest, but was the one that most lowered the level of TDS in each measurement, which means that its little roots were absorbing nuts like crazy. However, at Royal AK, which has a somewhat larger root ball than the rest, the nutrients dropped much more subtly. It also makes sense that if it costs you more to obtain the nutrients, you will develop a larger root ball to try to reach more of them
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