The HOT Magnum 250 is a poor biological filter by any measurement. It is very portable and I think it is intended to be only a particulate filter. Its filtration is either a thin sponge or a diatomaceous earth coating depending on which you set up. The Magnum 350 is a more conventional canister and can be used effectively to filter a large tank.
The cycle is proceeding almost as if you had not cloned your filter but had a decent bacterial content in your tap water to draw on. I would expect a typical cycle of that type to take 6 to 8 weeks. Don't worry too much about using 4 or 5 ppm until the very end of the process. Quite honestly, any measurable ammonia is enough to move your cycle forward. After all, you can only measure the part of the ammonia that the bacteria have not yet used, which means you are measuring the excess. At the last we run the concentration of the dose up to 4 or 5 ppm to ensure we can move a lot of ammonia through the system in a day. That means we have a bacterial population that will support lots of fish.
The cycle is proceeding almost as if you had not cloned your filter but had a decent bacterial content in your tap water to draw on. I would expect a typical cycle of that type to take 6 to 8 weeks. Don't worry too much about using 4 or 5 ppm until the very end of the process. Quite honestly, any measurable ammonia is enough to move your cycle forward. After all, you can only measure the part of the ammonia that the bacteria have not yet used, which means you are measuring the excess. At the last we run the concentration of the dose up to 4 or 5 ppm to ensure we can move a lot of ammonia through the system in a day. That means we have a bacterial population that will support lots of fish.