and for future reference and anyone else that reads this post, this is why surfactants are not recommended. just a brief summary from an article
They can be very lethal. The LD50 varies by species and by the type of surfactant. One species of fish may be fine with a level while another will die at a very low dosage.
If they are not immediately lethal they can cause issues with reproduction, juvenile development, and tissue damage to the gills that slowly kills them.
They can also cause a whole list of long term behavioral and physiological effects. Many of these are debilitating to the fish. These are generally caused by very low concentrations of the chemicals.
In more established tanks will a full healthy biota of microbes the danger of surfactants is less. However in a new tank with very little microorganisms the effect could be catastrophic.
So to be on the safe side. Keep them out of your tank whenever possible.
Guang-Guo Ying, 2006. Fate, behavior and effects of surfactants and their degradation products in the environment . Environment International, 32(3), 417-431 .
H. VON WESTERNHAGEN, 1988. SUBLETHAL EFFECTS OF POLLUTANTS
ON FISH EGGS AND LARVAE. FISH PHYSIOLOGY,, XIA, 253-346.
Lewis, MA, 1991. Chronic and Sublethal Toxicities of Surfactants to Aquatic Animals: a Review and Risk Assessment . Water Research, Vol. 25(No. 1), 101-113.
Partearroyo, MA | Pilling, SJ | Jones, MN, 1991. The Lysis of Isolated Fish (Oncorhynchus mykiss) Gill Epithelial Cells by Surfactants . Comparative Biochemistry and Physiology , 100(3), 381-388.
Vittozzi, L | De Angelis, G, 1991. A Critical Review of Comparative Acute Toxicity Data on Freshwater Fish . Aquatic Toxicology AQTODG, 19(3), 167-207.