The website says the tube style are safer than the tubless style as Blind posted. At the bottom of the webpage:
<span style="color: Blue">Contrary to what you have heard or been told you do not have to match a prefilter box with the pumps gph output. The prefilter will handle from a zero flow to its maximum flow rate, and anything in-between. In fact it is better to have a pump larger than you require and then using a ball valve (does not harm a pump to cut back flow) you can adjust to your liking.
Siphon tube prefilter boxes are preferable and SAFER to use than siphon tube-less boxes for several reasons. They are easier to clean, easier to maintain, easy to start, and do not require faulty check valves or unreliable secondary powerheads or "aquapump" to remove bubbles and air from the tube.
The water velocity through a siphon tube is faster than the water velocity through a tubeless design and therefore any bubbles generated flow right through a siphon tube. Bubbles do build up in the tubeless designs, that is why they have powerheads to hopefully keep them operating. These "tubeless" designs also pump air bubbles into your aquarium ruining the view.
Once started the siphon tube will ALWAYS restart and resume flowing water after a power failure or when you turn the pump back on. There is no need to restart the siphon tube.</span></em>
<span style="color: Blue">Contrary to what you have heard or been told you do not have to match a prefilter box with the pumps gph output. The prefilter will handle from a zero flow to its maximum flow rate, and anything in-between. In fact it is better to have a pump larger than you require and then using a ball valve (does not harm a pump to cut back flow) you can adjust to your liking.
Siphon tube prefilter boxes are preferable and SAFER to use than siphon tube-less boxes for several reasons. They are easier to clean, easier to maintain, easy to start, and do not require faulty check valves or unreliable secondary powerheads or "aquapump" to remove bubbles and air from the tube.
The water velocity through a siphon tube is faster than the water velocity through a tubeless design and therefore any bubbles generated flow right through a siphon tube. Bubbles do build up in the tubeless designs, that is why they have powerheads to hopefully keep them operating. These "tubeless" designs also pump air bubbles into your aquarium ruining the view.
Once started the siphon tube will ALWAYS restart and resume flowing water after a power failure or when you turn the pump back on. There is no need to restart the siphon tube.</span></em>
