Please note that there are 30 RadSliders in every one of the three templates of the FormView and when a particular mode is selected, only the slider controls in the corresponding template are rendered on the page. I would suggest using a Web User Control in order to define all repeating elements and controls on your page, so that you don't have to configure every RadSlider separately.
In case you want to speed up the page, containing 30 slider controls, you could split them in several ASP Panels and show only a part of the RadSliders by setting the Visible
property of the panels, if such approach is compatible with your scenario.
I hope this helps. Please let us know if you need additional assistance.
the Telerik team
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