Here goes. A little history first.
Been using my Q tank successfully since last November to Q my additions before adding to the DT.
First I Q'd 5 yellow tail damsels. No trouble, in the DT they went are thriving in the DT.
then I Q'd 2 Sleeper Gobies a yellow head and a Two Line. No trouble, in the DT they went. Both were great until the two line (my favorite fish) jumped out of the tank. :( Yellow head still thriving. Want to get another two line but they are rare around these parts.
I Q'd a Royal Gramma. No trouble, in the DT he went. Thriving also would not leave "his spot" in the tank for two months but now he explores the entire tank but still favors "his spot" Eats like a pig and has become the largest fish in the tank.
I Q'd a Flame Angel and a Coral Beauty together... not the best idea... there was relentless fighting the Q is a 20 high (not much space for them both) the flame was relentlessly attacking the Coral Beauty. In with the tank divider within 24 hours, they were not going to work things out. Broke the Q rules I know. Some fin damage to the CB from the nipping of the FA. With Peace returned and both eating well and on separate sides of the tank. The CB's fin damage fully healed and everything was going well. Only testing for PH/Ammonia/Nitrite/Nitrate all continuous 0's except nitrate and I'd do a 25% water change when nitrates reached ~20ppm. Both eating well still. I was getting anxious to put them in the DT and decided I would give them another week and if all was well they would go into the DT next weekend. A couple days into the last week the CB stops eating, still swimming around like normal. flame still eating. Water tests all the same. I tried feeding Formula one pellet with garlic, and "Seaweed Select Green sheet algae with garlic" CB still not eating, FA eating normally. day two symptoms CB not eating and hiding a bit... Day three of CB not eating I come home to a dead CB. flame angel is still ok and on his side of the divider. I cancel any plans of moving the Flame to the DT because I have NO CLUE why the CB died. several days later the FA stops eating. same pattern as the CB. dead three days later.
There's the Q's history. So I have NO CLUE why either of these fish died after what seemed to be going well after the initial fighting was resolved. Due to circumstances and timing I suspect a water pathogen has done them in or cyanide but no confirmation. So I break down the tank. Wash everything with 15% water/bleach solution, sponge filter, filter box power head EVERYTHING. anything in/on that tank soaked in 15% bleach solution for two days. emptied rinsed with tap water refilled and soaked everything for two more days with a fresh 15% bleach solution. Rinsed with tap water again. Let tank sit with fresh tap water and all goodies soaking in it for a few days. Emptied let dry and sit DRY for nearly a month. Refilled with RO/DI water put all the stuff that I soaked in bleach solution in the tank and let it soak in the RO/DI for a few more days. Emptied and refilled with RO/DI again and this time set the filters up and ran them with the RO/DI water (no salt) for a week. Emptied again and filled with salt water. Threw one small piece of live rock from my DT sump into the Q right next to sponge filter. I will discard this piece of rock when i remove it. used it to seed the filters after their sterilization. Tank has been cycling for over 6 weeks at this point. PH 8.2 ammonia is 0 nitrite is 1ppm and nitrate is ~25ppm normally i would say this is great and the cycle is almost done. BUT. my water parms have not changed AT ALL in 3 weeks. still PH 8.2 ammonia 0 nitrite 1ppm and Nitrate ~25ppm. i have not done any water changes during the cycle and my nitrite does NOT BUDGE hasn't in three weeks. anyone have any ideas on what i can do to help things along... I realize nitrite can take a while to drop... but it has been three weeks without a change. dont want to Q anything in the tank until nitrites are at 0 but am getting frustrated because i have been patient for three weeks and there has been no change. this cycle is in it's 7th week right now. obviously there is 25ppm of nitrate in the water so something MUST be happening. anyone...