fish emulsion fertilitzer?

[bluetexasbonnie]

Yes! (but it isn't as critical). The stated dilutions are usually for 'normal' plants, and cacti are not 'normal'. In general they disallowed - see forum rules in a lean, nutrient poor, hostile environment. They feel most at home with very dilute food. It is better for them to have barely enough than to have as much as they want.

One of the little appreciated 'facts' of organic vs. inorganic (chemical or ionic) fertilizers is that the organics tend to stay in the soil, waiting for the root to release the enzymes that release the active part from the organic part. In essence, organic fertilizers are release as the plant needs them -- which means that it is hard to over feed them. However if you were to keep dumping 'full strength' organic fertilizer on them for a long time, they can ultimately build up enough to start changing soil characteristics. At 'half' strength this would never become an issue for your cacti.