Please .... not one kilo each ten
Over the years I have discovered that not all divers pay special attention to the amount of weights they need. In some way it is also understandable, if somebody have the opportunity to dive only during the summer holidays can happen to forget how much weights they used (the log book can be helpfull ).
But it's important to not underestimate the value of the right weight, diving too heavy or too light can affect all the dive and in some cases can also affect the safety of the diver .
The control of the buoyancy is ,at the same time, one of the most important and most difficult skills to acquire. The difficulty arises because the variables that concern the balance are really a lot: the equipment, the environment we dive, our body, the way we breathe ..... practically everything. If we use a 7mm suit we will have a different balance than using a 5mm suit, the same if we use a steel or aluminum cylinder, the same if we use a 12 liters or a 15 liters, and the same cylinder, no matter if 15 or 12 o 10 liters, will affect the balance in a different way at the beginning or the end of the same dive. Understanding the importance and magnitude of these variations is not impossible but requires practice and care, the reward will be an appropriate buoyancy performance. There are also some kinds of “matemathical approach” to calculate the ammount of weights but mainly are not really trustable
The better way to gain experience about “buoyancy”is the practice,the use of mathematical schemes to calculate how much weights you need does not make much sense, our body is made from different tissues that react in different way once in the water, the fat mass floats while the muscle mass sinks, and a diver who weights 80 kg and is 180 cm tall will certainly need a different ammount of weights then a diver with the same weight but 150 cm. Tall.