I got the feeling my fishes were not quite as happy as they had been so I tested again and ammonia is spiking around 2ppm. Nitrite is still at 0 and nitrate is around 10-20ppm (I find this one really hard to read). Should I water change today or wait 24hr in the hopes that it's the spike before it falls? Also will I need to re dose with TSS after after change? Seachem isn't readily available in the UK, I've only seen it on Amazon. TIA Due to Rookie mistakes and bad lfs errors/ advice I'm fish-in cycling with a full stock (68l/ 18g, 2ft long tank). I posted here previously and got a lot of great advice. I did a 50% water change over 2 days and then seeded the tank with TSS. I also bought an API master test kit. I tested the water 48hrs after adding the TSS and the results were: PH 7.6 (this is normal for our area and the same that the fish were in at the lfs) Ammonia 1ppm Nitrites 0ppm Nitrates between 5-10ppm (however a baseline test shows this is normal for our tap water anyway). A repeat test today (5 days post TSS) shows the same results. Temp is pretty constant at 25c/ 78f I'm not over feeding (I feel like I'm under feeding them so I'm probably getting it right). I'm feeding flake with bloodworms as a treat every few days and will be getting some pellets as a treat for my corys next week. The fish are all active with good colouring and are not showing any signs of ill health. I just want to check that you think this is all ok and also whether you think my cycle is underway or should I add more TSS (I added a bottle and a bit as was correct for my tank size so I have 4/5 of a bottle left). Thanks in advance!