My husband and I have been keeping koi for 7 years. We upgraded over the years, so we now have a 10,000 gallon pond in the back yard. I'm in charge of measuring water quality, using chemicals to treat the pond, and watching the health of the koi. My husband is in charge of the equipment. I have learned you can never rest on your laurels. You need to test your pond regularly. I use API's testing kits. I use many of API's products and have always been happy.

When we upgraded, we first got a system off Craigslist (bad idea), and then we were able to save enough to get a really good system. We decided to keep both the old and new system together (bad idea). Everything was fine for a while until we had an ammonia spike bad enough that 3 new koi died before we figured out the problems. Through trial and error and money we discovered had 4 things going on. First, we discovered the system off Craigslit was poorly modified from a pool system (bastard) and built up ammonia. It's probably why he wanted to sell it. Our new system handled the extra load until it couldn't. Second, we didn't realize the water pressure in the pipes to the good system was too high and the clay did not have enough time to do a good cleaning of the water. Third, the pressure was so high the clay was disintegrating, so over time there was more and more ammonia and less and less clay to filter the water. I was at fault because I got lazy about testing the ammonia. I was like how could that much ammonia build up with that much water with that level of fish load and that much filtration, especially as we had never had a problem with ammonia? Whenever I tested for it it was no-existent, until it was so crazy high we were lucky not to lose more koi. We also did water changes regularly. The fourth problem was we did not know that our county started putting ammonia in the water, so every time we did a water change we were adding ammonia back in, even if it was at a lower level. So if you have issues, test your water source as well as your pond.

We used massive amounts of ammo-lock until we figured out the problems and corrected them. What ammo lock does is it binds to the ammonia to create a non-lethal version of ammonia. Your pond system still has to get rid of it, but in the meantime it won't be toxic to the fish. It's the next best thing to doing a massive water change (with water that does not have ammonia already in it). When you test your water it will still show as having high ammonia because it does (just in a non-toxic form). I know we would have lost more koi without ammo-lock.

So we threw away the bad system, added more piping to decrease the water pressure, added more clay to the filter, added the Cyclone to our system that removes fish waste so less ammonia builds up, and the county started using less ammonia so we don't have to use ammo lock on a regular basis. I test the ammonia regularly no matter what.

So, I totally recommend using this product until you can fix whatever the cause of the ammonia is.

Never used it because the pain would still show that they're has ammonia in it and I can't tell what type of ammonia it is

This product does work, but you have to understand HOW it works. It does not remove ammonia from your pond, it merely neutralizes it. So your test strips are still going to show a high ammonia level, although it is a SAFE ammonia level.
So how do I judge? Sluggish fish mean an application is needed, happy fish mean the water is fine. Best you can do with this product.

the only problem here is it works by neutralizing the ammonia, but because it doesn't eliminate it, the test kit readings will still be high so you don't have any way of knowing if the free dangerous ammonia is too high or not. I just guessed by the fact the fish stopped dying and swimming irregularly that it worked.

Used it on a brand new pond. Did exactly as described. I don't lose one KOI.