Cycling tank and water changes

[Hank82]

Ok I have to be honest, is there a possibility of messing up me tank for good (high ammonia levels) if I don't stay in the 4-5 ppm while doing the cycle? I have spend a lot of money on this tank so far and I don't want to get everything to toxic levels that stay, if that makes sense? Is there a possibility of the sand absorbing the ammonia and not getting filtered out.
thanks

 

[Coryloach]

Not really, a water change will fix it. Any issues will just slow down the cycle..
No need to be dosing 4-5ppm. I've always done it up to 3ppm, and also, wait until all ammonia goes down to zero before doing another dose. You'll never reach toxic levels that way.

After the cycle is complete, meaning the bacs are consuming all ammonia and nitrite down to zero efficiently in 24 to 48 hours, a large, near 100% water change should be done to remove all build up of nitrates. Ammonia and nitrites should be zero too of course before fish are added.