2 PCS Pawfly 4-Inch Air Stone Disc Bubble Diffuser with Suction Cups for Hydroponics Aquarium Fish Tank Pump

I bought this as a two pack. I followed the directions soaking for 30 minutes. When I hooked them up they had one airline to themselves. One only bubbled on 1/3-1/2 of the disc and the other less than 1/3 of the disc. The directions say if this happens get a larger air pump. I had 3 air pumps laying around so I gave each one there own air pump. These are good air pumps with two outputs and designed for 60 gallon tanks. I hooked up both outlets of air pump to one bubbler. Same amount of surface area of bubbles. I cleaned the stones with dirt as the package said. No different. I emailed the supplier twice, no response. Crappy product and crappy seller. I would give a one start but they do actually work, a little.

As some other users have written, there is an issue with the glue bond between the housing and the stone. I'm not sure why I decided to gamble, but sure enough the air only flows out of two large holes at the bond rather than out of the stone. DO NOT BUY THIS.

Not impressed. They do not stay secured to the bottom of Rez, which causes it to bang around against the root ball. If they do somehow stay secured all of your nutes and gunk gets underneath it and all over the black plastic.I usually just use the large 4x2 air stones but wanted to try these as they cost at least teoce as much, so they must be twice as good right? Nope! I ended up removing all of these to go back to regular air stones; as they work much better and cost half the price.If you want to try them you can have mine!

Like other reviews. Air leaks out one side where it’s not supposed to. At first some bubbles came through the disc but it didn’t take long for that to fail and now air only comes out on the side. Do not recommend getting. The casing and suction cups were nice though and stayed on the bottom of the tank even with a turtle. That’s why I gave it at least a star.

Liked: looks well made.Disliked: air bubbles only come out of the side, a small portion (see pics)Don’t buy. I bought 2 and they both suck. Hopefully the air bubbles improve with the rest of the stone in the weeks to come. I still use them though, lol. Buyers beware, laterz.