Platys In Filter

[Novembro]

Alright, so I posted this topic in the beginners section, but this is the second fish we have lost to this cause, so it seems like a slight emergency to me (at least).
 
Background, 15g cycled tank, all water tested and good to go (tested by me at home and tested by our fish shop). The tank is a Tetra with a Whisper EX20 and an Aqueon 50w heater.
 
Bought three platys last night to start the tank off and one continued to be sucked up into the filter. We attributed this first death to a nipped fin and small size. However, the second platy (female) was very healthy and swimming around the whole time. She seemed to be fine.
 
Again, the fish disappeared, only to be found dead in the filter. We are now left with one female (the replacement for dead nemo) and one male. We just tested the water again and recorded the same results as we did last week.
 
Is our filter too high? If that's the case, then we must change it out immediately as the tetra filter has no option for a slower setting. We tried putting a bit of sponge in the filter to slow down the intake, but that messed the filter up entirely.
 
I'm baffled! As a new tank/fish owner, this is quite disconcerting. Help

 
Edit: the replacement platy was sucked up just now. Was stuck onto the filter. I would assume we need a slower filter. We have tried our best to block off the intake so that the little guys won't swim close to it, and I don't know what else to do.

 

[Ninjouzata]

On your other thread it seemed the sponge you tried was a household one, but not sure?
Did you buy these fish from the same place btw? I am wondering if they're just bad stock and dying overnight and once fish die they usually get pulled over to the filter and so you find them sucked up against it.
 
I also think in the other thread you said you cycled your tank using the guide on this site, so all should be fine, but still, can you post the water parameters? Sorry I am not of much help, if any

 

[mhancock]

Try putting a big sponge round the filter intake, you may need to cut the shape.

This is often done by breeders to stop fry getting sucked up.

I'd also be inclined to get a couple of platties from somewhere different as they are normally lively enough to cope with high flow and yours may have been less than 100% to start with?