Hey,
What can I say... I am not a "perfectionist by the book" when it comes to water parameters but I do believe the stability is the key and so are frequent water changes.
My PH is always about 8.0- 8.5 and always stay stable even after 50% water change. Hardness is 150ppm which is not the highest I know but it works for me.
I "normally" change 30% of my water every week. I am almost always trying to use crashed coral substrate which makes my water hard when combined with rocks etc... Dolomite is also pretty good.
I use salts and Ph buffer when setting up the tank and ones the PH and hardness is stable I dont experiment anymore to boost one or the other and to achieve book values. I just found stability is the key!
About your Lufubu... How many did you kept in the colony? Is there possibility they just have killed each other while sorting the hierarchy out? Usually happens to small colonies (less then a dozen) they just can destroy themselves unless kept with some other trophs... Maybe its not a water parameters to blame?
Hey Maaxim thanks for the reply.
I've kept the Colony of 12 for a while, a few were holding and I did recently find a lone fry in the tank. As I had these in my classroom at school I had to take all the fish home over the holidays.
I agree with what you have said about stability being the key. This is where I may have gone wrong. On moving the fish I changed my usual routine which sounds very similar to yours, crushed coral substrate etc 20-30% water changes every few days, and decided to introduce the fish to my tang community and do a 50% water change beforehand. I used seachem cichlid salts and tang buffer for the first time. I normally use just cheap tang kH salts and a little pH up (with some epson salts) but decided to spend a bit more and use the seachem products, as this tank now has quite a bit of value in there. The pH of the water introduced was just over 9. Normally my water is around 8.2-8.6. I noticed the kH went up quite a lot also, to 200ppm from 140ppm. The temperature of the community tank was also slightly higher at 30 degrees.
I watched these guys stop eating and noticed one even had bloat. All the other fish I moved to the tank at home, came from identical water due to the three tanks cycling through the sump. The calvus, lelupi, troph debosi and morillo were super stoked. Colours looking so good. I don't think joining the new community was to blame for the Lufubu, and the water in both tanks had nitrate levels of between 20 and 40ppm to start. I just must have had too much salt in the water for the Lufubu and such sudden change in water chemistry killed them.
Hope others can learn from my mistake!