Cycling with Mix of Established Sand/Rock and New Sand/Dry Rock


New member
I'm making a slight upgrade from a 3-year-old established IM Nuvo Fusion 10g to an IM Nuvo Fusion 30gl. I'll be transferring my current sand (3-5 lbs), rock (8-10 lbs), and bio-balls (not sure how to measure the amount, could fill a 1-2 liter container maybe). I plan on adding new caribsea live sand, and another 20 or so pounds of caribsea dry live rock. So ~2/3 of the material will be brand new.

My livestock includes 2 ocellaris clowns, a skunk cleaner shrimp, an emerald crab, and an assorted CUC.

I have only set up brand new tanks before so I don't know what I should expect for cycling. What will this much established media do to the cycle time? Will there even be a cycle?

Thanks in advance for your feedback!


Staff member
RC Mod
expect 4-8 weeks cycle depending on proportion---I'd get those bioballs out of the picture as soon as you cycle. They're nitrate factories. I've cycled in 8 weeks with dry rock and sand and nothing more than a gallon of store discard water, back in the dino days. (And had no pests from it: blind luck.) You can help it along by dropping in a few flakes of fish food daily, and when it starts processing, you'll get your ammonia spike, which then will go away.


New member
I'd get those bioballs out of the picture as soon as you cycle. They're nitrate factories.

Thanks, Sk8r. I hadn't seen comments about nitrates with bio balls. To be clear, these are the MarinePure ceramic spheres, not the plastic bio balls so I think I called them the wrong thing. Regardless, does the nitrate warning still apply?

Michael Hoaster

Registered Seaweedist
Premium Member
I would think having 1/3 of your biological filter already established, the cycle would go considerably faster than starting from scratch. How long? Let us know, and you'll be adding to body of aquarium knowledge.

Yeah, you don't need the extra biomedia, regardless of the material its made of. It's great for nitrification, but the end product is Nitrate, hence the 'nitrate factory' label. In sand beds and live rock DE-nitrification can occur, leaving only nitrogen to bubble out harmlessly. You've already got plenty of surface area for nitrifying and denitrifying bacteria on your sand and rock.

Good luck with your project!


New member
I started two jar builds about ten days ago (one day apart). I used live sand along with dead (seiryu) rock; one jar had halimeda and the other didn't. I did use a dead frag for ammonia, and levels rose to about 1.8 to 2 for about a week; I've had no appreciable ammonia for two days in either jar, with nitrates at 2.0 in both (nitrites are also at 0, but am not sure if I can trust that). Either the live sand helped to make this a record-fast build, or the Red Sea test kits can't be trusted. Testing continues.


New member
Tank Update!

As promised, here is a breakdown of my experience upgrading from a 10g to 30g tank.

TLDR; There was no noticeable cycle when using the sand, rocks, and ~90% water from a 10g tank to a new 30g tank. However, all the usual signs of NTS were present, just at a greatly accelerated rate. Based on previous experience with new tanks it seemed like what normally takes 6 months to a year all took place in about 3 months. I'm sure I made plenty of mistakes, but tank is going well with tons of coraline, great softie and LPS growth, and a few hardy SPS.

Previous Tank:
Innovative Marine (IM) Fusion Nuvo 10 AIO
Eheim CompactON 600 Return Pump
Hydor Corelia Nano Powerhead
Eheim 25w Heater
1 AI Prime HD
1l MarinePure Biomedia
IM CustomCaddy and monthly purity pack replacements
~3 gallon displacement live rock and sand

New Tank:
IM Fusion Pro 30
IM MightyJet Return Pump
2 AI Nero 5 Powerheads
100w BRS Titanium Heater
3 AI Prime HD
IM ChaetoMax Fuge LED
IM NuvoSkim DC Protein Skimmer
2 IM CustomCaddy Midsize
IM HydroFill Ti ATO 5g
~10 gallons displacement live rock and sand
--- Added Later
IM AquaShield UV Sterilizer
Neptune Systems (NS) Apex Controller
NS Trident

Purchased equipment, new rock and sand, thoroughly cleaned and rinsed the new tank, setup new rock aquascaping, setup and reinforced cabinetry, and moved everything into place. This took about a month before setup day.

Setup Day - Dec 8, 2020
After a ton of reading and chatting with other reefers, I took a bit of a risk and transferred the sand, rock, 90% (9g) of water, and the livestock to the new tank all at once.

I moved the livestock and rocks (with living corals) to a clean bucket. I set up the new rock work, then mixed the existing sand with new sand and transferred to the new tank. Next I filled the tank to about 75% with new pre-heated saltwater. I then placed the old rockwork, topped off just enough to get the return pump circulating water, and let everything settle for about 30 minutes. I double checked temp, then added the rest of the livestock and original tank water.

Dec 21, 2020
0 ammonia, 0 nitrites, .25 nitrates, .06 phosphates. Diatoms, initial signs of dinos :eek: and possibly some green hair algae.

Jan 12, 2021
The Skunk Shrimp got caught in the Nero's openings in the back. RIP. Back covers are now on.

Jan 16, 2021
Neptune Systems gear added.

Jan 18, 2021
0 ammonia, 0 nitrites, 0 nitrates, 0 phosphates. Full blown dinos. Adjusted protein skimmer run time and ordered the UV sterilizer. Also increased feeding fish and corals to get nitrates and phosphates up.

Jan 24, 2021
0.5 nitrates, 0.13 phosphates. Yes! Nitrates and phosphate present, UV cleared up dinos in a week or so, and skimmer back to full time.

Feb 5, 2021
1.25 nitrates, 0.16 phosphates. Added chaeto to the fuge.

Feb 15, 2021
0.75 nitrates, 0.08 phosphates. Yup.

Mar 14, 2021
0.75 nitrates
0.07 phosphates
8.14 dKH
412 Ca
1372 Mg
8.04 Ph
35.3 Salt

Still working on the overall numbers a bit, but the tank has settled in really nicely.


New member
Original 10g

30g Setup Phase

30g January 2021

30g March 2021


New member
This is interesting, So you guys are saying the extra bio media in a sump can actually increase nitrates in your tank? Assuming you have enough sand and liverock in your display. I am sincerely asking since I have never heard this before.