Old dry coraline, new water. Ammonia? Other cleaning advice

[Fitz19d]

Title sorta has it. I have a 125g that's been down for a couple months I bought with a ton of dry coraline on it still bright pink/purple.

Once I fill it, will it cause a big spike at all, or so calcerous it's basically a skeleton? Was hoping to mostly fill and put new sand in then be transfering all the live rock and stock and last of the water from other tanks.

Next is some cleaning help. First time RR tank. The overflow has that very thin section before going to the larger plumbing section. The bottoms of the very thin sections had a lot of sand/gunk that I broke up with a metal rod. Given the tank is so huge/impossible to really move. Any ideas on cleaning it out? Just fill and hope most floats out since it's broken up? Hard to get any tools down there as it's like 1/4inch.

[Fitz19d]

Also, for sand, I read it several times a month or two back but now I'm forgetting again. I had aragonite that I ditched when I moved, been bare bottom while waiting for new tank to be ready.

For sand that's thin, was it better to have small vs "larger" granules. (But still not gravel sized?) Want to say I thought the smaller was better at being kinda packed and preventing detritus from getting stuck underneath. (Larger and things fall between/thru them) But on other hand small granules going to blow around via powerhead/very active goby?

[ynot65]

Viniger

[Sugar Magnolia]

You really want to clean the entire tank. The coralline is dead and when you fill the tank up it will turn completely white. Best to start with a fresh, clean tank. To clean it fill it up with warm water and white vinegar. If you can, a 50/50 is best. Let it soak overnight to loosen everything up. Use a sponge to swipe down the sides. Give it a good rinse and dry and you're ready to go.

As for sand, you definitely don't want sugar grain size. It tends to be blown about by powerheads. I like the Seafloor special grade sand.

[breiter3]

+1 to cleaning the coralline algae off with vinegar bath. It's just dried up calcium so it's not going to cause anything to spike, but it's good to start clean. Just make sure when you're scraping that the surface is good and wet. Dry scraping will almost always scratch the glass.

If you're going for a shallow (thin?) sand bed I would go the crushed aragonite route. Big enough that it won't get blown around by your power heads and can easily be vacuumed to cleanup any detritus before it builds up.

[Fitz19d]

No way I'll be getting 60 some gallons of vinegar to make 50/50. Guess I'll sponge/rinse the walls and scrape down. Or possibly fill and then remove the coralline. (Kinda balking at 120 gallons of tapwater would be pricey. Was more thinking if I had to just accept a longer cycle rather than a simple transfer.)

[pmark]

Put the tank on its side and cover the wall with paper towels then pour solution on it. Make sure to keep it wet

[breiter3]

No way I'll be getting 60 some gallons of vinegar to make 50/50. Guess I'll sponge/rinse the walls and scrape down. Or possibly fill and then remove the coralline. (Kinda balking at 120 gallons of tapwater would be pricey. Was more thinking if I had to just accept a longer cycle rather than a simple transfer.)

No you don't need to fill it up completely, just use a soak of 50/50 vinegar, or even 100% vinegar, and bathe the sides of the tank in it. The vinegar will help break down the coralline algae so it comes off with less scraping and scrubbing :)

It really does help