Almost Given Up... Need Advice

[SoloChromis]

Several years ago my 75g suffered a marine velvet outbreak brought in by a purple tang, wiping out nearly everyone. Problem is, I never *really* purged that tank of any remaining pathogens. I basically medicated the 2 survivors, then threw them back in and hoped for the best. After leaving that tank, with the 2 remaining fish, and adding no new fish to the system, I made the naive, and overly optimistic assumption that the tank was A-okay and that everything could go back to the normal routine. Bottom line is this - still to this day I lose fish for what would appear to be a "mystery", the last loss being my beloved quoyi parrot who just didn't seem to adjust to the 75g holding tank after a month of quarantine. I'm fed up, and have even recently considered donating the rest of my livestock to various LFS display tanks and giving up entirely, mostly to the guilt associated with taking fish out of their natural environment to place them in my tank where many seem to simply vanish after a couple weeks.
I love this hobby, but just recently it's become too much given all the losses and the nitrates I have been battling for quite some time. Quite simply I'm refusing to take any more animals into my care until I can truly provide a safe, healthy home for them to thrive in. My 2 ongoing issues seem to be what appears to be the remaining marine velvet from 3 years ago, and high nitrates.
I should mention that my coral is doing phenomenal (LPS, zoas, gorgs etc.), it's only some of my fish that haven't seem to be thriving in the past couple years. I have torn down my 120g and have plans to set it back up, but for now everyone is in my old 75g temporarily. For someone in my very aggravating, and upsetting position, what would YOU recommend?
As far as my renovating my 120g, my plans are to rinse out the tank/sump and plumbing with some diluted bleach, replacing my DSB with an inch deep layer of brand new Nature's Ocean live sand. I had planned on keeping my live rock, as I have some really nice pieces I have collected over the years, but if all that will do is reintroduce disease, I would replace it all. I am considering incorporating several crops of macro algae in the display to help with excess nutrients, as well as providing a unique look. As far as fish...
(1) Percula Clown (already have)
(1) Azure Damsel (already have)
(1) TB Springer's Dottyback (already have)
(1) Zebra Moray Eel (already have)
(1) TB Striped Fang Blenny (already have)
(2) TB White Spotted Pygmy Filefish
(2) Fathead Sunburst Anthias
(2-3) TB Assessor Sp.
(1) Marine Betta
(2) TB Sharknose Gobies
(1) Red Sea Mimic Blenny
(1) Hector's Goby
(1-2) Yasha Shrimp Gobies
(2) Blue Stripe Pipefish (if I can find a pair that's eating)
(1) Bellus Angel (female)
(1) Possum Wrasse Sp.

... I'm getting my broken LED fixture fixed, replaced the old crappy skimmer with a far superior Reef Octopus, and mixing up roughly 160g (sump/refugium factored) of IO Reef Crystals water and then dosing 2 bottles of Dr. Tim's One & Only (always had good luck with the stuff). After everything is settled I'll add the new sand, as well as some of the live rock, and after a couple weeks if all tests read out well I'll start slowly adding the fish, coral, and inverts back in.

Any suggestions would be more than appreciated, as I really am feeling down on my luck with my tanks. I should also mention I'll be quarantining all new fish additions for a minimum of 30 days :beer: Thanks guys

[d2mini]

I'd be inclined to find a home (temporary or permanent) for all livestock (QT and treat everything if plans are to put back in your tank) and then ditch all substrate and rock. Nuke the aquarium as planned. Ditch all the plumbing. Start fresh.

It's the only way you will truly know everything is gone.
Plus, who doesn't like new tank builds? :D

[PhaneSoul]

I would get rid of the sand, soak rock in bleach for a few days then soak in dechlorinator and rinse until it doesn't smell like bleach. I wouldn't put sand in immediatly, let the rock and water sit for a month or two after the nitrogen cycle is reeestablished so any excess nutrients in the rock are purged out by the bacteria, this will help with all the algae and excess nutrients associated with setting up a new tank. After detritus accumulation has slowed down then go ahead and add your live sand and check for a mini-cycle and if none add a fish and go from there.

If you could I would keep all your coral in a seperate tank until your main tank gets back up to speed and stability for them

But if your just going to ditch your LR there is a chance I'll take it, depends on price lol

[snorvich]

Do you know what parasite you are dealing with? Unless it is uronema, running fallow will fix the problem.

[OrQidz]

I was going to say just let it go fallow too. Why tear everything apart if you don't need to?

If you're constantly battling nitrates you've got a stocking or nutrient problem. I can't tell what all you have in your 75, or is it the 120? A purple tang would probably not be happy long term in a 75. Some parrots get pretty big (wouldn't it eat your rock/corals? I have claim total ignorance on parrots though).

As far as donating your livestock - you could have a velvet problem so the people getting them should know to QT for that for sure.

I salute your desire to fix everything and make sure things are right for healthy home before bringing in new fish. Turn your feeling bad into passion for doing things to their best, and you and the fish will be happy.

[SoloChromis]

I was going to say just let it go fallow too. Why tear everything apart if you don't need to?

If you're constantly battling nitrates you've got a stocking or nutrient problem. I can't tell what all you have in your 75, or is it the 120? A purple tang would probably not be happy long term in a 75. Some parrots get pretty big (wouldn't it eat your rock/corals? I have claim total ignorance on parrots though).

As far as donating your livestock - you could have a velvet problem so the people getting them should know to QT for that for sure.

I salute your desire to fix everything and make sure things are right for healthy home before bringing in new fish. Turn your feeling bad into passion for doing things to their best, and you and the fish will be happy.

I believe a huge part of my nitrate issue was my RODI water's TDS level, due to the fact that I had put off replacing the media, as well as my DSB which was left unstimulated due to an outbreak of pyramid snails, which killed off every mollusk in the tank, well as a large whelk that was sold to me many years ago as a fighting conch, that I had completely forgotten was in there until I found it chewing on the corpse of a *true* fighting conch that I had added. So basically I had a nutrient sink in place of a healthy deep sand bed, and dirty water in place of clean replacement water. My tanks have, for the most part, always been fairly lightly stocked. So basically I just need to revamp everything in the tank - sand bed, RODI water, hefty clean up crew etc.