Cloudy Water, Suggestions?

I had been running a 55G tank for 6+ years and had no issue what so ever with cloudy water. Last week on Tuesday, I purchased a 125G tank, brought it home, did not chemically clean it, just rinsed it out. I then used the water from my established 55G, the decorations, and the filter in my new 125G tank. I also had to add a bunch of water to top the tank off. I did switch substrate from crushed gravel in my 55 to pool filter sand in my 125G. For filtration, I have a fluval 406 canister (which was established from my previous tank) two sponge filters inside the tank, and a HOB sponge filter. The two sponge filter in the tank and the HOB were not established. I immediately did a water test and it came back with pH at 8.0 (a little high), Ammonia 0, Nitrite 0, Nitrates 20 PPM. The water was CRYSTAL CLEAR. After 2 days, I decided to try the API Proper pH 7.0. I added it and it worked really well, taking my pH down within a few hours. The issue ever since I have used it which was about 12 hours ago, my water has been cloudy? Should I be concerned or should I just let the tank go and it will clear itself up? I am concerned because I do have 10 Cory Cats, 12 Neon Tetras, and 3 Bala Sharks in the aquarium and I was going to go up to the LFS today to get some more fish but not sure that's a good idea right now.

 

Just wait 3-5 days...

 

Do a couple of 50% WC.

It's cloudy because the bacteria that WAS left behind isn't there anymore, causing a bacterial bloom.

 

How do you keep your 55G ph lower?

After battling to reach at least neutral (my tap is 8.2-8.4) I've gone to using Crystal Geyser bottled water (6.9) or adding Crystal Springs (very low ph) to my tap water for water changes because the ph lowering products create bouncing back. I think you have to use some stabilizer with that stuff. My ratio is 1 part tap water to 1.5 parts Crystal Springs.

Anyway, I 'd do some water changes to lower that nitrate....and I use Seachem Purigen - it's great. I have it as additional media in my HOBs. (ONLY use their prefilled bag or buy their special bag because the Purigen is very fine and leaks out of other bags)

You can put some of your 55G established media in your HOB, too if you have enough.

I can also recommend Seachem Stablity and/or Seachem Pristine which I use with water changes. (instructions are on the bottles for new tank that hasn't cycled versus maintenance).

 

Also, I just remembered Seachem Clarity. I'm doing a water change and have this in my stash but never used it - I've never had cloudy water more than a couple of hours. It sounds like it's made for your situation, though.