Although it is a good rule of thumb to water your succulent once per week, there are variations. Leaf burn can occur if you fertilize too often. The question is what amount of water are they going to need? The water you use should work. But to what extent? It is possible to use it depending upon the plant species used for industrial fertilizers. Monocarpic Agave species tend to be monocarpic. Here are my soil recommendations. One method to determine soil moisture is to use a moisture meter.