FYI, you can build them as well, I spent 8$ for a 20 gal.
Do a DIY search on how to make.......
However, they do NOT boost or increase and amplify plant growth in any way.
So that is simply put, a myth.
It's never once been shown in any study.
If you are more curious, you can set up a very simple test using your tank as model.
Turn the cables off, let things settle in for several month.
Turn cables on.
Look at plants, tank etc.
Turn cables off after a few months.
In the summer, many folk's temps go up too high to use their cables at all.
Plant growth is no different.
One can only concluded that the effects pose no added significant, measurable differences w or w/o cables.
After seeing these patterns for several years and on multiple tanks, as well as looking into the fundamental basis and reasoning for cables to begin with, none of the logic makes any sense, nor do the results obtained from 7 samples measured over 7 years for all tanks, and 10 years for 2 of the tanks.
The best anyone ever argued for cables was George Booth about 8-10 years ago.
But even he admitted they where not significant and the patterns he saw, (we both used the top of the line Dupla cables, far better and more accurate in terms of temps than the cheap knock offs today) he cannot say where from the heating cables.
Adding further to this, Tropica did a study to see the flow rates of no heat vs heating cables and found optimal growth at no heat applications, this was measured as a function of redox values, the main driver in aquatic wetland soils.
Such broad and long term work on this topic is really crushing to the argument for their use.
Regards,
Tom Barr