I recently experienced an ammonia spike in established tank of six years. I have done several water changes, added an ammonia lock and ammonia removal in my filter system and still the ammonia is in a toxic range. Can anyone help please? In my tank I have a large silver scat, a green scat, 2 Malayan angel fish, 2 black tipped sharks, a bala shark, a redtailed shark, 2yo-yo botia, a blue modesta botia, and a white severum.

Hi, net2tanz!

Greetings and WELCOME to the site! I just re-worded your question a bit so that it would attract more attention to those that know about such things as you are asking, and moved it from Introductions to this topic area so that it would get the most exposure to those who are best able to answer it. Introductions is for people to introduce themselves and we try to not ask questions there.

We would appreciate it if you would return to Introductions sometime to tell us a little about yourself though, if you would be willing to do that.

Thanks!

Thank very much I appreciate your help

You're very welcome! Someone will be along eventually who will have knowledge about what you are asking. Or, who could research the problem; how to solve it and get back to you.

I do know that there are a number of persons on this site who are really into fish keeping in various ways. However, please do realize that the most qualified ones who can address your question might not be logged in right now, and may even be asleep.

Sometimes, it does take a bit of patience to use this site. But, the results in being patient in awaiting answers can be great!

The best thing to do when you have a fully stocked aquarium and something happens to the cycle to cause a spike in ammonia or nitrite levels is to use bottled bacteria like active Biospira or inactive Cycle. Both products will keep the toxic levels low and quickly reestablish the aquariums cycle.

Can you think of anything that might have cause this? A change of something, gravel cleaning, large water and filter change at the same time, anything?

Thank you I also found out about the bacteria. The ammonia is still up a bit but better. The spike was caused by me over cleaning the filters and the tank. Too much to quickly.