Question about switching substrate in an established tank

[shollis2814]

I am considering switching out my substrate from CC to sand once school is out and summer begins. My tank is a 36 gallon bowfront with about 55-60 lbs of live rock in the tank and sump.

I have read/heard two schools of thought about the safest way to do this. 1) is that most of the nitrifying bacteria is in the rock, not the substrate and to 'just do it'. 2) is that I risk a re-cycle or mini-cycle, which I do not want.

My play it safe method that I am toying with is to start now slowly removing some of the CC I can get to, may 20%. Give it some time for the bacteria in the LR to play catchup if necessary, and then take out some more. In other words, work my way down slowly to a bare bottom tank, and then to a major rescape/sand bed this summer when I have a large chunk of time to do it right.

Input?

 

[Joeganja]

It's possible yes but like you said it's gonna take a long time. Many don't know that bubbles of hydrogen sulfide can form in deep sand bed and disturbing a lot of it at a minimum period of time can ruin your tank. I'm not 100% that's possible in your case because you have coral crushed but I'm sure someone more knowledgable will be sure to comment and help. But i would recommend using carbon media when doing that switching. Also make sure to do plenty of water changes.

 

[shollis2814]

Thanks. Also, my CC depth is minimal, maybe an inch or less at the deepest. I don't think I have many anaerobic pockets, though I could under some of the rock.

 

[Joeganja]

Thanks. Also, my CC depth is minimal, maybe an inch or less at the deepest. I don't think I have many anaerobic pockets, though I could under some of the rock.

Yeah just do little by little like week by week so you have the least amount of fluctuations possible.

 

[Joeganja]

I am considering switching out my substrate from CC to sand once school is out and summer begins. My tank is a 36 gallon bowfront with about 55-60 lbs of live rock in the tank and sump.

I have read/heard two schools of thought about the safest way to do this. 1) is that most of the nitrifying bacteria is in the rock, not the substrate and to 'just do it'. 2) is that I risk a re-cycle or mini-cycle, which I do not want.

My play it safe method that I am toying with is to start now slowly removing some of the CC I can get to, may 20%. Give it some time for the bacteria in the LR to play catchup if necessary, and then take out some more. In other words, work my way down slowly to a bare bottom tank, and then to a major rescape/sand bed this summer when I have a large chunk of time to do it right.

Input?

When the term "just do it" is being said never ever listen to that. Those are thoughts that can work but also fail so it's 50/50. But what's good is you have more rock than your tank is supposed to have so you have a lot of bacteria.

 

[brandon429]

it is quite easy to sw substrates, or fully clean existing ones. the work is hard, the biology of skip cycling is totally easy.

that graph above reinforces our process...it involves exposing nothing delicate to rotting waste, that's it. that's the whole procedure, the order you take apart and reassemble the new setup will allow you to fully skip cycle the new setup and lose nothing.

-high points-

don't factor bacteria at all, they are there in plenty no matter what you do.

with bac now not considered, we can focus on the total risk...detritus. the act of moving tanks, or getting 100% water change wont kill the rocks corals fish or any small benthic animals. exposing them to rotten sandbed waste by acting hesitantly sure will, so we do a deliberate process for moving tanks or changing beds.

remove all rocks and clean them of detritus and store in buckets separate from all other animals.

fish and corals in their own buckets ideally

this leaves only dirty sand and dirty water in the tank now, isolates are safe from harm cuz they were removed first before any cleaning action. remove the entire sandbed take apart the tank and put back together with brand new sand wet pack caribsea, ideally, and rinse that massively before use. bacteria are not factored, you aren't killing them by rinsing the new sand either, they aren't factored just thought id mention that pre rinse detail.

acclimate all life back in new tank

 

[brandon429]

I have done skip cycles in threads for the purposes of tank cleaning, moves, upgrades to the tune of a hundred times its very easy to do.

the only problems come from hesitation at critical moments, we have those mapped out. not concerning over bac causes hesitation, so we eliminated that aspect too, narrowed only to the critical moves

 

[shollis2814]

Thanks, brandon429. That is the plan. I have a large plastic tub dedicated to the tank for emergencies. I plan on siphoning out some top water and placing fish, coral encrusted rock and frags/corals in this tub with heater and airstone. Another one for rock only (though I know there are critters in there, it helps with rescaping to know which rocks have corals and which don't). Keeping about 1/2 the water so I am ultimately doing a 50% water change while removing the substrate.

I have had sand in other FW tanks, so I know you have to rinse, rinse, rinse. I plan on doing that as well, all with RODI water. One of the reasons I am waiting until summer is to start early so I can block off plenty of time.

 

[saltyfilmfolks]

Whats your bio load. How old is the tank. A pic would be great.
My .02. It would only be beneficial. Yes the bacteria is on your sand, lots of it. You are correct. Also smaller grains more surfa
But in IMO its also where the majority of the nitrate factories are in most tanks.
Caution is a good thing yes, but, If youve never done a tank tot tank transfer, its actually quite easy. and extremely beneficial.
I did my last one in less than 6 hours.
@brandon429 My friend here is quite fearless it seems to most, but that comes from experience, hence his Just do it stance.
But if you read his work, its a VERY calculated method with understanding of the risks and experience breaking up the myths so prevalent in the hobby.

FWIW, there is no such thing as a mini cycle.

I did my 30 gallon in one day. nothing died.

 

[shollis2814]

I know mini-cycle is a bit of a misnomer. It's sort of what I refer to when you add bio-load and the bacteria increases to match food source, but I get what you are saying. Sorry for the confusion.

36 Gallon: royal gramma, lantern bass, neon goby, percula clown, tuxedo urchin, banded serpent star, coral banded shrimp, small emerald crab, various cleanup crew (low on these, need more)
Corals from largest to smallest: Hollywood stunner, Frogspawn, Duncan, Pavona, /GSP colony, 3x zoa frags, button polyps, clove polyps, 4x small blasto colonies, 2 small cup corals, small favia frag

Everything before the / in the coral list are larger. Everything after are on frag plugs.

 

[brandon429]

let me link you a cool sand rinse thread below, and, state some negatives in procedure ive seen that did cause harm during the move:
http://reef2reef.com/threads/the-of...ead-aka-one-against-many.230281/#post-2681445
1. the keeper wasn't exchanging sand, he was rinsing and reusing. he didn't have enough sw for the rinse, so he ended up putting in some detritus which does cause a mini cycle. when we say rinse sand, we mean harsh rinse, illegal in six coutries, such that no clouding can occur. if he would have fully rinsed, no loss, no recycle.

2. a second keeper was rip cleaning a giant, old, crudded up tank. he had rocks covered in algae that had pent up detritus inside the rocks, as much as a dirty ol sandbed would normally hold. we had him part out his 300 gal reef in the right order, but I forgot to tell him to house rocks sep from fish...so, when moving the rocks and removing the algae that allowed the waste to pump out from the rocks into his fish holding bin...mini cycle, loss.

those are the two majors, all else went as planned

 

[brandon429]

that list of animals is good to know, to frame the xferring bioload. Unless you have the ultra-bare live rock setup, rare, your current live rock will filter those which is how people go to bare bottom quickly if they prefer...sand bac are incidental in 99% of reefs. using wet pack sand still brings in some, but we factor the move around not needing the sands help at all, then what it confers is extra safety.

the detritus is so darn critical because it will compound the required waste oxidation far beyond just the animals alone...detritus mud carries giant bacterial loading, oxygen consumers, and when exposed to a holding container there really might not be enough active surface area + fish in holding...setting up your new tank with zero, zero detritus is the golden key and bacteria just wont factor at all, what will transfer over is plenty if its not a compounding detritus issue


we rinse in tap water in that thread above for good reason:
-tap rinses with a short dwell time do not sterilize (bac doesn't factor here, they are tougher than we give them credit for)
-saves saltwater for just the final rinse portion...so you aren't moving tap into the new reef. the tap allows for unfettered rinsing till purely clear...no clouding, this is being deliberate and using rules of microbiology to repeatably do things in reef tanks



I have a 25 min video am editing that shows this action in my ten year old pico reef, a system so small and without dilution that one calc mistake will recycle the whole thing:

-vid shows parting out reef and laying rock and corals on the counter, not even underwater. am doing this to show the toughness of bacteria and reef substrates. I don't have junked up rock, so this is safe.

-vid shows me tap rinsing my live sandbed for 15 mins straight, final rinse in saltweater to evacuate it from the grains, then reassembling the entire reef back on top of pristinely white rinsed sand. the rinsed sandbed still has nitrifiers. if 15 mins of tap rinsing was a sterilizer, surgeons wouldn't need the fancy scrub in with all the chems and manual debriding. they would just submerge arms in tap water and begin. tap is filthy, we should check the colony counts from local water reports and then amplify those x 100 after measuring from our output piping.

-vid shows best coral extension ever in 24 hours, all micro life intact, and im running algae free such that I don't even have any cleaning chores for a long while till I get lazy w the reef again. vid shows me doing harsh things to my reef only so that large tankers can plan accordingly. what they fret doing is my normal tuesday

 

[saltyfilmfolks]

Its a common misnomer, it does conjure up the wrong image in most peoples mind. Tus its become my little pet peeve.
A cycle can only be broken by catastrophic event, long term neglect or bleach or bleach really.

So if you get your pieces together, sounds like you have a good plan for itn I would take a day to do it, maybe two depending on your equipment.
Personally I dont think the little at a time thing is good. You scoop crap into the tank once a week? then more? "mini cycle comes to mind:D.

I drained the whole thing, caught the fish, pulled the rock, scooped the sand. All the poo and scary stuff was in the bottom of the tank.

If you are using live sand yea there may be some cyano or green algae on the glass. but hey thats reefing.New tank phase My transfer was because I has so much PO bond to sand and on several rocks (long story).
By using a refugium, a canister filter, 5 gal weekly WC and increasing my lighting, I pulled the po off the rock, then out of the sand(curiously, in that order).

 

[brandon429]

hey shollis when finished can you link us the pics and details and outcome, id like to link back to our example thread. sandbed work is a dirty risky thing heh

 

[saltyfilmfolks]

It's possible yes but like you said it's gonna take a long time. Many don't know that bubbles of hydrogen sulfide can form in deep sand bed and disturbing a lot of it at a minimum period of time can ruin your tank. I'm not 100% that's possible in your case because you have coral crushed but I'm sure someone more knowledgable will be sure to comment and help. But i would recommend using carbon media when doing that switching. Also make sure to do plenty of water changes.

Hydrogen sulfide can actually develop anywhere. Recently a member lost a tank due to it forming in a bio media canister.

And yes there is the fear of that kind of build up. But there is also the fear of a plane hitting my tour bus(long live Randy!)
That pic is of a DSB gone bad. When the proper research is done on sand beds. it is all oxygenated and flow through the entire bed is import and especially in a you one. Especially when people have a dsb AND NO WORMS.
I poke mine with a stick kinda regularly, cultivate worms, and my Talbot damsel was now torn it to shreds recently and dug giant holes. (no "Mini cycle" BTW)
I think the author of the pic should have named that better. or its fear mongering.

 

[shollis2814]

hey shollis when finished can you link us the pics and details and outcome, id like to link back to our example thread. sandbed work is a dirty risky thing heh

Sure thing. I can do a picture journal of the process.

 

[shollis2814]

OK, next question(s).
As I plan this, I want to make this the last rescape for a while (ha!). For some of my rocks with encrusted corals (Cyphastrea) or mats (GSP). How do I balance taking my time and letting epoxy set on the rocks, and keeping them alive? Up until this point I have been doing a stack and prop method, but since my tank is tall, I don't feel comfortable with stacked piles that high and I lose a lot of my more intense light zone. It may be that I have to put those rocks in first as a base to keep them underwater. I know many corals spend hours at a time out of water in tidal pools, but I also know it varies by species.

 

[saltyfilmfolks]

OK, next question(s).
As I plan this, I want to make this the last rescape for a while (ha!). For some of my rocks with encrusted corals (Cyphastrea) or mats (GSP). How do I balance taking my time and letting epoxy set on the rocks, and keeping them alive? Up until this point I have been doing a stack and prop method, but since my tank is tall, I don't feel comfortable with stacked piles that high and I lose a lot of my more intense light zone. It may be that I have to put those rocks in first as a base to keep them underwater. I know many corals spend hours at a time out of water in tidal pools, but I also know it varies by species.

look at the marco rock systems. Its a portland cement. sets up pretty quick like minutes, from what ive read. same theory as "hydrolic cement" sets under water. so maybe a BIG tub to work in.
And youll have to just prioritize.:eek::confused:
dont worry about light. focus on stable water, flow and temp.

 

[MrReefBuster]

I did just that on my tank. Here's my video. There's a couple more on the whole process. Watch them all. Hope this helps.