Interested in completely redoing my rockwork on a mature tank. Best practices?


New member
I’ve had a small (10-30g) saltwater tank for about a decade. Currently it's a ~30g JBJ nanocube. When I started, I didn’t put too much thought into the rock-work. I didn’t know what would work well or what I’d like. Over the years, I’ve done a little chiseling and gluing to the main structure, but it’s definitely a large “Monolith”. How much attention I paid to the tank waxed and waned as my life has changed. During one of the rougher/busier times in life, I made the mistake of letting some of my Green Star Polyp onto my main structure. It’s healthily grown to take over most of the rock-work, and while it is quite pretty and mesmerizing (looking like wind-waves of tall grasses in a wet meadow), I’m ready to just retire the 'uninspiring' rock and create something brand new and exciting. However, I’ve never done a complete re-scape before… Here’s what I’m tentatively thinking:

1. Go to my LFS and buy ~20lb of MarcoRocks. Set up a little space on my basement work-bench for assembly (Probably by placing lots of cardboard down and sketching my tank's footprint with sharpie marker).
2. Break the rocks apart, glue them together… Spend a week or two assembling something, stepping back for a few days and evaluating what I’ve done so far, adjusting, etc. Take as much time as I need to make a structure I think would work well for me.
3. Get a Brute bucket and fill it 50/50 with water from my main tank and brand new saltwater.
Question: I’m assuming by using some of my main tank’s water, beneficial bacteria would colonize the rock and therefore be less of a shock to my tank's biome when it's introduced. Is this naïve? Are there negative unforeseen consequences I’m not considering?

4. Place the new structure into the Brute bucket, along with a heater and pump. Let it cure for a couple of months.
Question: I’m thinking maybe 3 months? Should/could I add some purple-up?

5. Once the new structure is cured, take out my old rock and break it apart. Keep fragments as islands or trade into my LFS for credit.

How does this plan sound? Any of you guys try something like this? Any lessons learned? Any advice? Many thanks!


New member
Sounds like a fun project. Letting the rock mature for a while in a bucket with a pump is reasonable. Don't know that you need a heater unless it's outside. No light so no reason to add purple-up yet. Make up your salt water and just add the crud from your skimmer/filter/sand bed to get live bacteria or add one of the commercial start-up bacteria products. 3 months sounds like a long time to wait. It's bacteria, will be millions of them. If you're doing a total tear-down and clean-out then would worry about the fish. If it's just the rock, then I might still monitor my ammonia/nitrites at the start. My experience has been that no matter how you prepare the rock once it gets the light on it you will get diatoms and algae. Hopefully your nutrients are low and your parameters are otherwise OK and it just cycles through until the corals and coralline algae take over. Why don't you start fragging your desirable corals as soon as possible so your plugs will be ready to go. You may be able to salvage some of your old rock for now or a future project. Share or trade-in the leftovers. BRS TV did a recent video on glueing rock and aquascaping. Can probably search for it on their website. Good Luck.

Sugar Magnolia

Mother of Dachshunds
Staff member
RC Mod
Sounds like you have a solid plan. I've done similar with cycling rock in a bucket with a powerhead and heater. IMO a heater is needed to keep the beneficial critters/bacteria alive while it's cycling. Any extended cooler water will have a negative impact because the rock is used to tropical water temps, optimally 74-78 degrees.