No but if you are just using a single tub (I am confused by your posts do you just have a lone tub?) I would NEVER go with a rack they are a pain to hold ambients and a nightmare to clean. I would just invest in a PVCx enclosure I have three and they are completely problem free for me at 68-9º I have no extra effort to hold correct temps rather than a rack. I have just over a 1000$ in mine at this moment.

4inch and 17 inch flexwatt the lower tub is in the 'summer mode' with the end with holes out not in.
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insulation; the rack is a closed PVCx rack as well.
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i have no yet needed to add the silver band to the tubs yet.