Toxic Algaefix

[BGPufferMama]

Algaefix almost caused a mass death within two hours of all seven of our pea puffers last night. I dosed tank according to volume, and within two hours, puffers were listless, floating/sinking, breathing heavily, and had turned an extremely dark color. I mean I seriously thought they were dead. We were starting to get a little hair algae, nothing major, so there’s no way it created an apoxic environment that quickly. I have used the same bottle to dose our 10g Molly tank, as well as a heavily planted snail bowl I keep on our counter with no issues with the mystery snails or mollies.

I searched extensively for existing threads on this, and cannot find any consensus or clarity. I joined this forum specifically to raise awareness about what happened to our pea puffers, as there isn’t much evidence of this occurring.

Setup: 20 gallon tall hex with river sand, larger plants I forget the name of, some artificial, two pieces driftwood, water lettuce, and duckweed, no air stone, exterior hanging filter. Zeo carb, purigen, fluval phosphate remover pad in filter (yes maybe overkill, but accounting for feeding of fish by a 9YO and don’t want ammonia spikes)

Parameters tested with dip sticks immediately following removal of fish, and also API testing kit (I triple tested because I was shocked Algaefix would cause this).
Ammonia: 0
Nitrite: 0
Nitrate: between 0-5 ppm
Phosphate: .25ppm
Ph: between 7.6-7.8
KH: 120ppm
GH: between 30-60 ppm

So, it HAD to be the Algaefix. Parameters were unchanged. I removed the fish to a pitcher and dosed with StressGuard and Prime. I’m not sure how to explain it, but it almost looked like the puffers slime coats were coming off. They turned a super dark color, and even their eyes got very dark. If I hadn’t been panicking I would have taken a photo.

After three hours in the pitcher, they started perking up. I did a major 40% water change with distilled water+replenish, and replaced the zeo carb filter and added fish back around 1:30AM. Everyone was fine this morning and happily ate their bloodworms.

Has anyone else experienced this?

I really wanted to warn everyone in advance that this could potentially happen to your pea puffers. I will never use Algaefix again in their tank. On that note, any safe algae treatments?

[Pufferpunk]

Yup, I hate that stuff!
https://www.aquasabi.com/aquascaping-wi ... e-aquarium

[BGPufferMama]

Thank you! Definitely leaving the lights on too long every day. Any algae eaters that can survive with pea puffers?