About a month ago, HTSL brought the above observation up re different pellet shapes but I didn't believe it was addressed or discussed fully as most US reefers did not seem to encounter the same problem with skimmer at that time.
In the last 3 days, reefers in Hong Kong discovered what appeared to be plastic pellets mixed in with regular biopellets. Many of them complained their skimmers stopped working for days and even weeks after starting the BP. Here are some of the pictures posted in the HK Reef forum showing the different pellets in the same bag.
Those BP sold in HK has Chinese labelling besides the standard label.
Those pellets on the left are the NP Biopellets and those on the right are what HK reefers called plastic pellets.
Some HK reefers even did a burn test to show the two pellets are indeed having different chemical and burn characteristics. See the linked video below.
The video explained the burn test in Chinese. Let me translate. The "plastic pellets" were shown first which are "thicker" than the biopellets. The video separated the biopellets to the left and plastic pellets to the right. In the burn test, the plastic pellet was ignited with a cigarette lighter and it combusted easily on its own. According to the tester, it smelled like burnt plastic. The biopellet did not ignite just melted.
At first many thought it was certain retailers who were scamming the reefers by adding fake pellets to boost profitability but several retailers went to the forum and defended that they purchased the NP Biopellets directly from the authorized distributer.
http://www.youtube.com/watch?v=ozh7CkAh9JU&feature=player_embedded#
When I read about the issue, I remembered HTSL from UK raised the same issue about a month ago so I thought may be the problem is not limited in Hong Kong but originated early in the distribution channel and may be even at the factory. Even with the manufacturing process changed, how can two different pellets ended up into the same bag?
My questions are:
1. Did anyone notice different pellets size in the same bag of your purchase?
2. If you did, how well was your skimmer working after you started the BP?
3. Is there anyway to test and identify the true biopellets?
Personally I have no problem with my BP and my skimmer works as it should. I still have about 500ml of unused BP in the original bag and I did not notice different pellet shapes.
I hope Jean Paul or someone from Aquarium Specialty can give us some insight into this.