Pawfly Aquarium Air Stone Ball 2 Inch, Airstones for Aquarium Fish Tank Bucket Hydroponics Pond and DWC Reservoir, 4 Pack

I bought these in June and just replaced all tubing and the air stones in our fishpond today for the winter. NONE of these air stones work as they are supposed to. Two of them have a tiny bit of bubbles coming out around the connector glue. This is clearly a manufacturing defect. I have some aquarium glue that I will seal the glue that is already there. If it works I will do the same to the other three. If not, I'm out the $15 I paid in June. I'm not sure why it's so difficult to find air stones that actually are all made with consistently good quality! The big take away from this for everyone: Test ALL air stones upon arrival for proper function!UPDATE (12-08-2021) - Just to check to see if it was possibly the air pump we were using, I purchased one of these from Amazon (VIVOHOME Electromagnetic Commercial Air Pump, 20W). I used a deep bowl of water and attached the air stones, one by one, to the pump, turned it on and I got tons of bubbles coming out of each stone. I am changing my rating from a 1 to a 3 because there are still quality issues with the seals around the air valve glue, but with a more powerful air pump, these do put out a lot of bubbles throughout the entire stone.

I have ordered these multiple times.These air stones are good size and well weighted, with a nice chromed connector.They have no trouble staying down in a tank or pond (unlike many other smaller stones).They produce a nice amount of fine bubbles. Not consistently though. There is some variation. Try 4 balls and one will be coarser and another like super fine.The reason I'm not giving them 5 stars, is that they still only last about 2 years because the area where the connector is glued in will break simply detach / break off from the stone, when you move them or pull them up for some cleaning. The stone material stuck to the glue just breaks off from itself.I have not attempted repairing them, and simply order a new set.At $6-7 per stone ... value is hard to say yay/nay ... but they have been the best air stones that I have tried so far, and with the AMZ convenience, I just re-order as needed.

When they are sealed and not chipped they produce tons of micro bubbles and a great airstone. Though after buying a 4-pack and 2 of them were chipped and had uneven black sealant where it wasn't adhered to. They did give prompt service to replace those 2, But then, 1 of the 2 replacements they gave me still had bad sealant- like they glooped it on around the opening and even after soaking over 12hrs would just leak air bubbles directly around the black sealant instead of forcing it thru the ball's air-stone. Definitely get ahold of manufacturing cause they're hurting you guys and get some quality inspections done before product gets "finished" prior to sending... When I had properly sealed and non-chipped stones, they work amazingly but quality is very inconsistent-

When I started my DWC project last fall I used large air stones such as these in my buckets - seemed to work quite well to provide the dissolved oxygen needed to keep my girls happy and thriving. I started reading about the use of 1/4" drip line tubing to make a "diffuser / aerator". Seemed like a viable option so tossed my large air stones and made a dozen drip line-based diffuser / aerators. Seeing the results after several months of drip line-based diffuser / aerator use I've come to the conclusion that no drip line-based diffuser / aerator configuration can provide the amount of dissolved oxygen needed to supply a root-choked 4 gallon reservoir. so back to large air stones it is!

I bought these because of the great reviews. These stones instantly turned my water milky white. I took them out and started changing water, but it was too late. I lost all my fish. These stones must have some toxin in them. Maybe I was sent a bad batch, but it's not worth the risk.

They pump a lot of air. They're less expensive than the ones that have suction cups that you can mount inside your bucket/tank but let these sink in the bucket I'm doing DWC hydro in. These are probably best for hydroponic use since they probably wouldn't look great in a fish tank if they were visible.

Decent price. I’ve been using these in my hydroponic veggie tubs and they are doing what I need them to! Seems like it puts out a lot of bubbles if you connect a strong enough pump. I have a large pump feeding 4 of these and it’s working great.

No air leaks around input like many other stones for sale.Air flows freely through the stone, better than other stones for sale.