yes you did miss that part, I did have 4 fish

Sorry about your troubles:sad:

I would say also, that it could have been due to not letting the salt mix for long enough....mix for at least 12 hours before your water change....I have a 20g rubbermaid tote(like $8 at wallymart) that I use to pre-mix my water in... an inexpensive heater and power head is used to keep it at tank temperature and mixed.

Do you shut off flow to the tank for the couple hours it takes to do the water change? No flow for that length of time is bad and could have caused the "crash"

There are two answers to this cycling question, the one that people want to hear, "cycling can be done in a few weeks", and the one that people don't want to hear, or choose to ignore (with varying degrees of success). While in theory a tank starts and can end its cycle within a few weeks, I personally would not consider it cycled, others may disagree. While the ammonia-nitrogen cycle enables fish and other living things to live in the tank without those toxic chemicals, this does not necessarily mean that the tank is finished with the FULL cycle in my opinion.

This is where the second and less favourable answer comes in. The FULL cycle can take up to a year. More things continue to go on in the tank after the initial cycle. For example, silicon and phosphates from live rock and sand are slowly released. This stage is where we tend to see algae and diatom blooms. The presence of these nuisances are an indication that you have silicates and or phosphates. This is where the tank is really JUST starting to balance itself out, as stuff leaches out, they are consumed by nuisance algaes until they are eventually and hopefully depleted. All the while, your bacterial culture is trying to keep up with your bioload (feedings, poops, pees, etc). The act of feeding can also throw chemicals into your tank. It can be quite a turbulent time for the tank. The more fish/critters, the more stress you add which the tank needs to account for. This is why everyone says, "take it slow". Give your tank and everyone in your tank time to adjust.

Anyway, not meaning to sound like a know it all (because trust me, I'm far from knowing it all! :-D ).. just sharing my experience with my tanks and cycling over the years. There will surely be other opinions on the matter.

ok so im starting to understand more about this. the LPS that I go to informed me of only the first one and not the second one and everywhere I read nothing talks about why you need to go slow when there is no problems. when it does talk about going slow it only talks about watching the first cycle your tank goes through and not the second.

I know many people that took the slowes road (2months between fish even years after setup) and I know some that have added 4 fish the first 2 weeks they brought the box home.

I know im new to the SW world and trying to make it work and Im starting to feel even asking questions is not good enough unless you are asking the correct question but you got to know the correct question to got the correct answer.

That's the kicker in this hobby.. As no two tanks are alike. What might take one tank a year to cycle might tank another tank 6 months due to other variables (the type and amount of rock and sand added, the type and amount of fish added, the type of salt added, the size of the tank, etc..). There are so many variables it is mind numbing to think about sometimes. This is why some people get away with being able to stock heavily after a short(ish) cycle while some people can struggle to maintain their tanks even after a year.

It is one part luck and one part experience. The veterins in the hobby still face some of these issues that newbies face, but the difference is that their experience has gained them knowledge to aid them in managing the issue. This is also where going slow helps. The first time you are presented with a salt water issue can be daunting. However, If you've taken things slow it affords you the time to figure things out before they escalate. Kind of a margin for error. If you speed into things that margin for error shrinks rapidly. Next thing you know your tank has crashed over night!

did you have airation in the bucket after you moved them?

Some info gaps with respect to your water change regimen? Are you using tap water to make up your water changes or do you have a RODI system? I started the hobby using tap water treated to bind the chlorine, but it's not something I would recommend. One of the best investments I've made is getting a RODI system for purified water.

I do fairly large water changes, about 25 to 30%, all at once. If I understand your water change procedure, it does not sound very efficient, seems like a lot of extra work and you may be well advised to make some changes there. Not sure this is the cause of your crash, but it should help keep things stable in the future. By ?taking out 2 pails and adding 3 buckets over the course of several hours? are you not removing some of the freshly added water you added previously? Perhaps I misunderstand your procedure, but I think it's best to remove all the water you intend to in one shot, then add all the fresh in one shot. This may not be feasible the way you're currently set up, but I'd suggest, as mentioned already by another member, you get a larger container to mix and heat your fresh salt water. Invest in an extra powerhead and small heater to get the new water to the right temp etc. Allow the water to mix at least a day before your water change. Floating pails of freshly mixed new water in the tank to get them up to tank temp seems like a lot of extra effort in order to do a water change. Hope things work out a bit better for you in the future, best of luck.

Yes I remove all the desired amount of water I intend on replacing first before I add any new water to the system and I picked up a rubber tub last night and just looking for an old powerhead to make the water changes more affective. Yes the way I do things is lots of work but I do not have lots of room in my condo to have a fancy setup.
I stopped using tap water and started using purified bottled water (the 5 gallon jugs that you fill up at the grocery store) about a week ago and never had any problem with that water. Is that bad water to be using for my thinking was if it is purified and good enough for me to drink why not them?

Using the grocery store water is a good start, but ultimately it's going to be another chore and expense that would be better addressed by getting an RO DI system. I'm pretty sure that the water from the store is RO (reverse osmosis) only and it will still have some TDS (total dissolved solids) in it. The DI (de-ionization or demineralization by ionization) stage of a RO DI system will bring the TDS of your water to 0 so you're mixing your salt in absolutely pure water. Check out some of the threads and info on RODI systems and you will find plenty of information. The initial investment may seem costly and although I don't know what your store charges for the bottled water, in the long run you will have better results and save money with your own RO DI system, especially with a 72 gal tank. The trips to the store for water will get old fairly quickly. As mentioned I do fairly large water changes on my 77 gal, about 25 gallons each time and I would not enjoy hauling that amount of water from the store every few weeks.

Just a few thoughts to throw out there.
Do you have a ground probe. Maybe you have a short somewhere it will kill your fish.
What about that prime you added maybe it is a bad bottle and the chlorine killed them.
Also having the circulation off for the water change dropped your oxygen levels to low.
Just some things to think about.