Hello everyone, I have a 30 gallon (112 l) tank that has been cycled since March 13th. I used pure ammonia to cycle it and ammonia readings has been at 0 ppm, nitrite has been 0 ppm and nitrates has been between 5 - 15 ppm ever since. In my tank I have several plants, rocks and driftwood. One of the pieces of driftwood was added the day before I started having issues with ammonia. The piece is made for aquarium use and has been boiled and left in a bucket of water for more than 24 hours. In my tank I also have 2 BN plecos (2 - 3 inches). One male and one female. There are also 5 Amano shrimp and 10 RCS. The male BN pleco is fanning wigglers at the moment and has been fanning in his cave since the 17th this month. I also have one pregnant RCS. All seem to be doing good, although they did a little better before the ammonia became an issue. Some of my Amanos has turned a little darker and blue-ish, which I've read is a sign of stress while the female BN pleco seems to be a little hyperactive. Since the first day I tested and my ammonia was at 0.25 I've done more frequent water changes. Instead of changing 25% once a week I've been changing 25% 2 - 3 times a week. I thought it would go down slowly, but when I tested my water today it was still at 0.25 ppm. I did a 45% water change and tested the water 30 minutes later which now read 0.50 ammonia! I treat my water with AquaSafe and that's what I've always been using. I feed my BN plecos and shrimp frozen food, flake food and pellets. The fertilisers I use are Tropica Premium Fertiliser and Tropica Specialised Fertiliser. I've been using the Premium one since the beginning but bought the Specialized one later on. I use both in the doses suggested on the back of the bottles. I've made a little timeline to help you get a better overview of the different events: March 20th: 4 x Amano shrimp added to tank March 31st: 2 x BN pleco added to tank April 6th: 5 x RCS added to tank April 17th: Female BN pleco has laid eggs April 18th: New plants added to tank April 18th: 5 x RCS added to tank April 18th: New plant fertiliser purchased April 20th: Driftwood added to tank April 21st: Ammonia reads .25 ppm April 21st: 25% water change April 23rd: Ammonia .25 ppm April 23rd: 25% water change April 24th: Ammonia .25 ppm April 24th: 25% water change April 25th: Ammonia .25 ppm April 25th: 45% water change April 25th: Ammonia .50 ppm Please help, I don't know what to do. From the looks of it water changes aren't helping at all and that's my only go to solution, when the problem isn't illness. Only when I made this post I realized that the ammonia issue came since adding the driftwood, but I really don't think that's the problem, though I will be removing it from the tank to see if it has any effect. Any thoughts, ideas and comments are welcome. Thanks for reading!