We’ve written before about Walmart failing to keep its shelves stocked, but here’s a story about a different kind of neglect at the nation’s largest retailer. Shoppers at a New Jersey Walmart say the store was allowing the live fish in its pet department to fester in dirty, unfiltered water with dead fish sitting on the bottom of the tanks.

“It was a nightmare,” one customer tells the Mendham-Chester Patch about the filthy tanks she discovered when she tried to look at the fish with her grandson. “Most (of the fish) were dead, and rotting in the tanks… Many were still swimming — starving, freezing, choking on foul water full of ammonia and algae.”

Customers told Patch that the tanks, which had gone dark with pollutants, had been unplugged for about a week. When the grandmother tried to complain to management, she says she was told the manager was unavailable and that the pet department manager was “out to lunch.” She waited an hour to eventually be helped by a store associate who sold her the least ill of the fish remaining in the tank.

When Patch reached out to Walmart HQ, the initial corporate response was that this store had stopped selling fish months earlier. Patch replied with photos sent in by customers showing dead and dying fish in these dirty tanks.

That got Walmart’s attention.

“This is unacceptable,” said a company rep after seeing the photos. “There are protocols in place that were not followed, and associates (in the pet department) will be retrained immediately.”

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