Adding substrate to a running tank?

attml · Oct 16, 2021

Greetings,

I was in the hobby approximately 10 years ago and had several tanks including a 120g SPS dominated bare bottom / starboard tank. I got out of the hobby for a while and must have forgot some of the hard lessons I learned the first time through because the sandbed I choose for my new tank was fine sand. This is an issue because it is getting blown around preventing me from adding the proper amount of flow needed for my mixed soft, LPS and SPS tank setup. The new tank is a 40g breeder with mainly dry rock that was seeded with some live rock. I currently have 6 hearty fish (4 damsels, 2 Photon Clowns in the tank and a few frags (Duncan, Zoos, Turbanaria, Sinularia, Digitata). I also have Astrea Snails, Blue Leg Hermits, Green Mythrax Crabs and a Cleaner Shrimp. I am running some mechanical filtration / carbon and some Phosban to keep my phosphates in check and have an AquaMax 1.5 HOB skimmer. My plan is to turn off all of my equipment, even out the existing fine sand bed and to then add a layer of the Carib-sea Agra-Alive more coarse crushed coral substrate overtop the existing sand bed. My questions are should I pull out my frags first and how bad do you think this procedure will jack up my fish and inverts? I know the ocean gets stirred up all of the time in storms but wasn't sure about the level of dust that would be stirred up and its affect on my livestock? Since I am adding the more coarse live sand I can't really rinse it first. Any thoughts or considerations of how I would proceed would be greatly appreciated! Thank you very much!

Mark

My former 120g

Current 40g Breeder

fishface NJ · Oct 16, 2021

Even though you bought live sand, it is no more than sand with a bottled bacteria added. I would suggest you wash it to remove the silt from it first. Once it shows it's clean, do a final rinse with RODI water. Get yourself a wide PVC pipe. Create a funnel for the pipe. Use the funnel and pipe to add sand to your system. Place one end of the pipe at the bottom of your tank and feed the other end with sand. If you cleaned the sand well, there will be no sand silt if using the funnel and pipe

Billdogg · Oct 16, 2021

I started my current DT with sugar fine sand. ALthough I like the look, it was blown all over the tank and I ended up with almost none in front and a 6" layer in back. Time for a change! What I did was siphon out all the sand from one side and replace it with very well rinsed Special grade. It still made for a slightly cloudy tank, it cleared within a day or so. The following weekend I did the same to the other side. Now, the substrate stays more or less where I want it.

I didn't remove a single coral. I did move the corals that were on the sand to the other side while I did the job, but then immediately moved them back once the new was in place. Didn't lose a thing. In fact, if anything they looked better afterwards.

hth!

I added the new sand as described above. I think I used a piece of 3" pvc. Any smaller would take way too long.

kittenbritches · Oct 16, 2021

fishface NJ said:
Even though you bought live sand, it is no more than sand with a bottled bacteria added. I would suggest you wash it to remove the silt from it first. Once it shows it's clean, do a final rinse with RODI water. Get yourself a wide PVC pipe. Create a funnel for the pipe. Use the funnel and pipe to add sand to your system. Place one end of the pipe at the bottom of your tank and feed the other end with sand. If you cleaned the sand well, there will be no sand silt if using the funnel and pipe

That's an excellent suggestion. I was going to suggest you rinse it (a LOT) and carefully lower scoops to the sandbed for minimal dust poofs. The pvc pipe route is much less labor-intensive, for sure, but you'll want to be thoughtful about distribution and how much you disturb the existing substrate.