Thank you for your interest in our japanese bathtubs！
From your description, I guess you are consideting our kadomaru tub.
-> “kadomaru-S” nostalgic hottub 850×630
In this case, the length of the planks (to be mounted side by side like in a barrel are pre-cut (final height = 740mm = 29″).
For this reason, we cannot simply extend the height.
We have the option of cutting custom material for a taller kadomaru but this would increase the cost in a higher proportion than the benefit you can enjoy
Another option consists of making a box-like custom tub with the height to match your requirements.
If you let me know the plan size you require, I can prepare a quotation.
You can refer to the standard tub sizes for reference ->-> ofuro price list
Or just go for the sizes you like (a custom size is not more expensive than an equivalent standard size)
◆fizz balls: I do not know the composition but I am afraid it would stain the wood.
You can use some neutral bath salts, anyway the whole concept of the hinoki bath is to enjoy the natural aroma without any addition.
We are looking forward to working with you and remain at your disposal for any question/problem.
With Best regards,
Bartok design Japan Co.
Manager: Iacopo Torrini