Understand being in Pakistan with the availability of supplies.
Those white pads are polishing pads and yes clog very fast. As you found out . The normal pads with that filter are Black /fine , yellow/ medium , blue/coarse. Experiment ! Try only the blue / coarse pad on very bottom were the dirtiest water comes in filter then all bio rings or ball’s on top plus the bio rings or balls in the tank first for a week and observe. Then take blue / coarse pad out and replace with the yellow / medium pad on bottom , see any difference in water. You can even place blue/coarse pad on bottom “and” yellow/medium pad on top of it then fill filter the rest of the way with bio balls or rings. Which combo give better results. Don't forget to crank down that filter some with the valve . None will be perfect “until” the good bacteria starts to hold and work for you. Experiment ! Will take a few weeks to get a good cycle going then maintain it.
1)Bubble sponge filter // in photo on left front, round black sponge with the air line attached to the green middle. Those are sponge filters use in shrimp tanks , if you want they do work but to me just takes up swimming room. Your call , either way ok.
2) Aliexpress not much on choices. The cheap ones (rings) are ok …33085 .
Only problem I have with the black ball type with sponges in them , are if you use them at the bottom of tank they try to float some. You have to pop them open and squeeze the air out let them let suck up water then pop back together. But they don’t always pop back together they are cheaply made. Rings will sink and stay , plastic ball tends to float . Use the plastic balls in the filter since you have them.
3) For the tank a small box 500g is about one pound should be good for the tank to help. If for just the look you can add more down the road.
4)The balls you have use them in the filter , amount will depend on if one or the two pads are used.
5) Do not use detergent either !
6)On the rings or balls do not waste the extra money on the activated type. Any good seeded bacteria with them will be dead by the time you get it. Just a marketing gimmick !
7)Watch the size on any of the ball type you buy , come in 3/4” to 1 1/2” in size. All work the same. Most ring type are about the same size.
Or just for a different look for in the tank volcanic rock does look better but maybe being in Pakistan cost more ?
http://americanaquariumproducts.com/Volcanicrock.htmlTo be honest any color pads “not used” in the filter placed in the tank , will work to hold the good bacteria ! Like what the bubble sponge shrimp filter is doing. Place a rock or a piece of slate on top of them to hold them down , low tec but works ! Be creative to hide them but don't block the water flow to them !Experiment with that first, try what you have already ! In my DIY filter days I used plastic kitchen pot scrubbers from the dollar store and worked.
Look in photo gallery for threads / links for photo's and or a few videos on Piggley . You can see results with a turtle media setup in filter like we are talking about along with a well cycled tank provides . Give you across the board all numbers at (0) when testing. Yes I'm an old timer and can tell without testing what the water needs but a good drop test kit get all more exact. All 0's. Cycled and maintained ! There are several ways to do this but for me this is basically free letting nature do most all the work ! With no chemicals either. Use of carbon yes but I have a different method for that.