Green tinted crushed coral

[mshan217]

I have a 125 gallon tank with a few corals. I ran my tank as a glass bottom for years. Under a recommendation of a lfs I put crushed coral on both ends of the tank in front of the live rock only with some regular aquarium substrate in the middle. My crushed coral has a green tint to it and can't tell about the brown aquarium stuff. My nitrates are high. I vac the bottom twice a month. A also run a phosphate reactor and another one with carbon in it.
I have had the tank for 14yrs and the substrate on the bottom for about a year. I any suggestions.

 

[lmforbis]

The green is algae and the brown is probably diatoms. Crushed coral is not a good choice for saltwater. It holds too much crud in it causing problems like algae. The only recommended substrate is aragonite sand.

 

[mshan217]

The green is algae and the brown is probably diatoms. Crushed coral is not a good choice for saltwater. It holds too much crud in it causing problems like algae. The only recommended substrate is aragonite sand.

How much sand would I need for my tank. What is the possibility of making my fish sick when I remove the old cruddy stuff

 

[lmforbis]

Take the crushed coral out slowly a little bit every week when you do water changes. Once it is out you can add sand. How much is up to you. My tank is a 120, I think I put 2 bags of sand in it. Only enough to cover the bottom. That is how I liked it but it is a personal choice.
Keep an eye on your ammonia with a seachem ammonia alert badge. I’d have some prime on hand if it goes up.