I second getting rid of the crushed coral. It will lead to issues down the road.
2 1/2 to 4 inch sand bed will be better. Live sand being the best.
You can go with sand (not play sand, to much junk in there) and buy repllenishing kits to get the required life into your sand bed. The little critters will sift thru the sand and keep the upper layer oxygenated. The deep bed will help with nitrates.
Sand is also better for fish that like to borrow or eat alge from the sand bed.
The coral can also end up causing nitrate spikes from gas trapped between the coral.
The wet/dry filter can also pose a problem with nitrates.
A skimmer will help get rid of decayed organics that float on the surface of the water allowing for better light penetration and gas exchange (more oxygen in the water and more CO2 out).
You can make or purchase an overflow that will use a syphon to fill the overflow box and drain to a sump (the tank under your stand).
Or you can drill the tank and build an internal overflow. You most likely have a tempered bottom to your tank, so drilling the back would be best.
Since it sounds like you are already setup the external type would be best.
Do a search on sumps, you should find a lot there. It also keeps most of your equipment out of the tank.
The guy I bought my stuff from used air in his tank, everything was covered with salt. Took days to clean everything up, had to repaint the stand. It even caused one of his lights to burn up. Lucky for him he was home at the time.  |