Turn over is basically a recommendation that is very subjective. If x 3 gets all the nutrients to the four corners, then all is well and fine. However, as plants grow, the flow can change around the tank. I have a 240l tank that requires a theoretical x 22.5 turn over due to the heavy planting and hardscape restricting movement in certain areas.
To be honest, fishless cycling and planted tanks just don’t go together I`m afraid. Once you make the link light + ammonia = algae, you will see why. Tanks should be cycled with no light IMO.
If it is a planted tank you want, do yourself a favour and bypass the fishless cycle. Get the CO2 non limiting and stable, and then look at either EI dosing or TPN+. There are stickies in the planted forum that explain plant nutrients and the Estimative Index.
With sufficient plant growth, you will find that any ammonia is efficiently removed by the plant mass. Spend a few days getting the plants showing signs of healthy growth, and you are on your way. Running excessive CO2 at the start really helps to kick start the growth. Hopefully, if done correctly, you will slowly develop a bacteria colony, but you will have been able to add fish long before this (remember to bring the CO2 back down to 30ppm).
The initial stages of setting up a planted tank are about getting healthy plant growth at the expense of algae, not growing a huge bacteria colony with 5ppm ammonia that will reduce in numbers when in competition with the plants, and an algae bloom because the lights are on for the plants.
IMO, a fishless cycle should mean no light and no plants!!!!!!
Dave.