External Filter Intake And Tiny Shrimp

I've got some concerns with completing the stock for the forest floor tank.
The tank has a Fluval FX4 filter, and I'm worried that the intake (pictured) will not be safe for the tiny shrimp I have in quarantine.
The bumble bee shrimp (Caridina cf. breviata) are quite small, and could possibly get sucked through the intake.   

I've found a few options, and was wondering if anyone has any experience of them, or had any other ideas.
The first filter guard I found was this https://www.amazon.co.uk/Switty-Aquarium-Filter-Guard-Shrimp-16mm/dp/B07F66VM97/ref=sr_1_9?ie=UTF8&qid=1550741002&sr=8-9&keywords=shrimp+guard . The reviews seem to be mixed, with some saying it has sharp bits, and has fallen apart within 6 months.

A slightly sturdier looking one is this https://www.amazon.co.uk/sourcingmap%C2%AE-Plastic-Stainless-Aquarium-Shrimp/dp/B00K830U8G/ref=sr_1_7?ie=UTF8&qid=1550741002&sr=8-7&keywords=shrimp+guard , and the colour may make it less visible in the tank.

Another option is to use the intake that comes with the FX4, but put some coarse filter sponge on the inside.

I'm guessing all options will reduce the water flow through the filter, but as I have a much bigger filter than I need, this shouldn't be a problem. I'm also guessing that the filter intake will need quite a lot of cleaning with so many tiny plants in the tank, but that would be preferable to losing the shrimp.

I might put a spare filter intake "basket" into the quarantine tank today, to have a look at the shrimp size in comparison, and estimate how much of a problem this is going to be. In the mean time, any advice would be very welcome. 

Thanks @Sue I'll get a pre-filter and see how it goes. 

I've only bought 10 shrimp, so I'm hoping that they are going to breed. I'll have to keep a close eye on things when cleaning the substrate, thanks for the warning.