Exactly. And I also don't consider the vast majority of catfish species to be "high energy carnivores". More like low energy opportunistic feeders, with some species leaning more to the carnivorous side of the equation.
Crude Fat (min.): 20.00%
Way too high for any species of tropical fish, including catfish, so I would highly recommend feeding this food very sparingly. (if at all) Monitoring how your fish appear in your tank won't give you an inside view of fat deposition around their liver. There are studies involving carnivorous species fed high fat (17%) diets, which resulted in excess liver deposition, which if fed over a prolonged period would result in necrosis of the liver.
If you are rinsing & soaking the food, you are also losing the vast majority of the water soluble vitamins contained in the food. With only 50mg/kg of vitamin c, you don't have a lot to be wasting to begin with.
Also, I think there's a lot of confusion with regards to "grain free" diets.
Fish aren't dogs, most species of fish, and certainly most catfish, can assimilate a certain percentage of carbohydrate with no problem, and whether those carbs originate from grain (such as wheat) or potatoes, will make zero difference to your fish. Catfish in general can assimilate more carbs than many species, and unless low cost, difficult to digest, carbs are being utilized there is no major health difference between a grain based carb, and any other form. In fish food carbs/starch are used as binding agents, and as a cheap form of energy. With a (min) 20% crude fat content, and a 19.2% carbohydrate content, all of the excess has to end up somewhere - it doesn't simply get excreted by the fish, such as the case with excess amino acids. (protein) Carbs that aren't utilized by a fish immediately, eventually also get stored as fat.
This dog food may be a cheap alternative, but I certainly wouldn't consider it a healthy alternative, at least not for a fish.
IMO your best bet would be to stick with the 10mm NLS, and supplement with frozen food from your local market. Your fish will be getting the best of both worlds, sans the high fat content.
HTH
(We just moved. The old guys always wanted the update on how the fish were doing...) Anyways, they had a massive sale on flounder, tilapia, seafood mix (muscles, clams, octopus, shrimp, squid, etc.), shrimp, and catfish chunks. Yes, I fed catfish chunks. At first I was like, no that's wrong. Then I figured my TSN had already demonstrated that she loves her catfish by shredding my ID. So, I bought it, and didn't feel bad for a moment. 
