How much live rock is ideal to seed an otherwise dry rock tank?

[Daniel@R2R]

OK, I realize I'm likely to get at least 1,000,001 opinions on this, but I'll give some context to the question.

I'm looking to upgrade a 50g tank to a 200+g tank. I'm also looking at starting a small office tank. I've only got the rock that is currently live from the previously set up 50g reef. It's been active for the last 6 years, so there's plenty of good stuff in it.

So, since I'm planning to use mostly dry rock in the big reef and add the previously used live rock to it, I'm wondering if there's a magic ratio that will kick things off well. I'm also considering taking a little of that live rock and adding it to the scape in the smaller office nano to kick that one off to.

I do realize that it's probably a "the more, the better" kinda scenario, but I'm wondering if there's a tipping point (I'm kinda assuming there is). Like what's the minimum to get good results, and then where do diminishing returns start to set in? So I guess I'm looking for a ratio window of sorts...

Does this make sense? If the above is confusing, just ask questions and I'll try to clarify what I'm saying. LOL

Thanks for the help, guys! Excited to have this discussion.

 

[Spare time]

I would think that adding rocks from different places and materials would be best (i.e. maybe some that was in the dark, other in the light, different material, etc.) in order to get a wider range of microbe friends

 

[X-37B]

Here is what I do with very good results.

I used 50% live 50% caribsea on my 120. So about 35lbs each.
I just setup this 18" nano with all live rock from my frag and remote fuge system.
Also had 2 baskets of eheim substrate pro in my 120's sump for about 3-4 weeks.
And one with Matrix in my frags sump.
All the rock is 2 years old from my frag as I moved some to the fuge awhile ago.

So no cycle.
14 frags and 2 small colonies from my 120 and 45 frag systems.

Water was from both systems also from my monthly water changes.

Tanks 9 days old an I am already dosing 6ml a day of ESV 2 part to keep my alk stable.

Live rock works wonders, imo.

 

[MTBake]

I can't answer this exactly but can give some context.

My current tank was started with 20% live rock from gulf live rock and 80% dry from marco rocks. I'm a little past the 2 year mark and finally feel confident adding harder to keep coral in this tank. I had a 20 gallon before and that's where the gulf rock came from. That tank was growing all sorts of life within a couple months. My current tank does not have nearly the diversity that one had.

 

[mfinn]

If it were me, I would add as much of the live rock that's in the 50 that you can spare to the dry rock and also add some bacteria in a bottle.

 

[Atomicus]

1/3 live rock 2/3 dry rock at a minimum. Preferably half half. Else get more uglies for more time

 

[CK00020]

As much live as you can do, if I started over again I would go with all live the savings isn’t worth the headaches.

 

[Chrisv.]

This is a trick question. Put the dry rock in a Rubbermaid tote to age and buy all live rock for your tank!

 

[GoVols]

buy all live rock for your tank!

+ 1

 

[jda]

You are going to get a 10001 opinions, but choose which ones to follow well.

First, you don't need much to seed, but what you seed needs to be ready to be seeded, just like earth needs tilled, fertilized, etc. Dry/dead rock that has been in water for long enough for the caked in organics to be removed and the phosphate be unbound from the rock, can quickly and efficiently take the new life from the seeded rock. This takes a long time in a vat before being put in the tank, but, as you know, this can take years in the tank.

Part of the reason that live rock is so good is because it is phosphate free and not caked with dead organics way down inside that need years to be removed.

Second, you have to know when to seed. If the rock is not ready (above) then a lot of the good stuff on the rock can die before it has a chance to seed. Higher residual N and P can kill a lot of the microfauna on the rock, but usually the bacteria, coralline, worms and some pods can live, which is still good. If you want the starfish, all pods, etc., then they tank will have to stay with a tank with parameters not-far from the ocean. ...so you might not want to seed fresh dead/dry rock right away, but knowing how long to wait can be tough to know from tank to tank.

Third, you need to understand how 1 effects 2 like I described... like actually get it. Most just ignore it or gloss over it. Think of it as putting corn on top of untilled and unprepared earth... it is going to spoil before the earth is ready. I don't mean to be condescending here, but most just do not get this and it is too important since you asked and obviously care.

Fourth, don't listen to anybody who tells you that bleach, vinegar or some acid is all that you need. ...just not true. All of these can help with some acute things on the surface but still do not all of the things in number one. You still need more than this.

If you need to do a bunch of dry rock for budget build, then get it in heated saltwater for a few months, at least. Get something in there to introduce bacteria and test the phosphate after a week. It will be high and might continue to climb in the months to come as the bacteria starts to break down some of those caked in organics which not only breaks down into residual N and P, but they also uncovered some more aragonite structure that will unbind even more phosphate. You need to treat a few times a week with some Lanthanum Chloride (cheaper and easier than GFO) with a skimmer or filter sock on the tank (or both)... and keep doing this until the P is like 1 PPB after a week or two of sitting. When the P stays low for a few weeks, then the rock is done unbinding and getting the decay out. This can take months and months, if not longer - all rock is different and there is no way to tell but you basically have to start bacteria to eat that caked in crap and also give time for the P to unbind.

Of course, you know what happens if you skip some of this... a year or two of the uglies.

In the end, just figure out the cost, effort, etc. and see what you want.

You should be able to get cultured pacific rock to go along with some Atlantic rock if you want even more diversity.

Lastly, don't underestimate used real live rock. Even though it can be full of nasty algae, phosphate, etc., you can get it back to life fairly quickly and faster than getting all of the caked organics out of dry/dead rock. There are a million threads on how to "cook" rock out there, or we can help... but it was really common and very effective before the dry/dead rock craze. I still will take/get all of the real live rock that I can, even if it was in a neglected tank... I have a rubber made 150 just for this. If you are in a larger market, be on the lookout for tank breakdowns and stuff... we are seeing more-than-normal tank breakdowns locally. When this is done, it won't be full of pods, worms, starfish and the like, but it will have bacteria be phosphate free and ready to accept life from the seed rock. If you can, start plenty early and try and do this, IMO.

 

[DocRose]

You are going to get a 10001 opinions, but choose which ones to follow well.

First, you don't need much to seed, but what you seed needs to be ready to be seeded, just like earth needs tilled, fertilized, etc. Dry/dead rock that has been in water for long enough for the caked in organics to be removed and the phosphate be unbound from the rock, can quickly and efficiently take the new life from the seeded rock. This takes a long time in a vat before being put in the tank, but, as you know, this can take years in the tank.

Part of the reason that live rock is so good is because it is phosphate free and not caked with dead organics way down inside that need years to be removed.

Second, you have to know when to seed. If the rock is not ready (above) then a lot of the good stuff on the rock can die before it has a chance to seed. Higher residual N and P can kill a lot of the microfauna on the rock, but usually the bacteria, coralline, worms and some pods can live, which is still good. If you want the starfish, all pods, etc., then they tank will have to stay with a tank with parameters not-far from the ocean. ...so you might not want to seed fresh dead/dry rock right away, but knowing how long to wait can be tough to know from tank to tank.

Third, you need to understand how 1 effects 2 like I described... like actually get it. Most just ignore it or gloss over it. Think of it as putting corn on top of untilled and unprepared earth... it is going to spoil before the earth is ready. I don't mean to be condescending here, but most just do not get this and it is too important since you asked and obviously care.

Fourth, don't listen to anybody who tells you that bleach, vinegar or some acid is all that you need. ...just not true. All of these can help with some acute things on the surface but still do not all of the things in number one. You still need more than this.

If you need to do a bunch of dry rock for budget build, then get it in heated saltwater for a few months, at least. Get something in there to introduce bacteria and test the phosphate after a week. It will be high and might continue to climb in the months to come as the bacteria starts to break down some of those caked in organics which not only breaks down into residual N and P, but they also uncovered some more aragonite structure that will unbind even more phosphate. You need to treat a few times a week with some Lanthanum Chloride (cheaper and easier than GFO) with a skimmer or filter sock on the tank (or both)... and keep doing this until the P is like 1 PPB after a week or two of sitting. When the P stays low for a few weeks, then the rock is done unbinding and getting the decay out. This can take months and months, if not longer - all rock is different and there is no way to tell but you basically have to start bacteria to eat that caked in crap and also give time for the P to unbind.

Of course, you know what happens if you skip some of this... a year or two of the uglies.

In the end, just figure out the cost, effort, etc. and see what you want.

You should be able to get cultured pacific rock to go along with some Atlantic rock if you want even more diversity.

Lastly, don't underestimate used real live rock. Even though it can be full of nasty algae, phosphate, etc., you can get it back to life fairly quickly and faster than getting all of the caked organics out of dry/dead rock. There are a million threads on how to "cook" rock out there, or we can help... but it was really common and very effective before the dry/dead rock craze. I still will take/get all of the real live rock that I can, even if it was in a neglected tank... I have a rubber made 150 just for this. If you are in a larger market, be on the lookout for tank breakdowns and stuff... we are seeing more-than-normal tank breakdowns locally. When this is done, it won't be full of pods, worms, starfish and the like, but it will have bacteria be phosphate free and ready to accept life from the seed rock. If you can, start plenty early and try and do this, IMO.

This is a very interesting read!!! Would there be any adverse effects to the process if you just do this in your display tank for those months, rather than a Rubbermaid? Obviously having just the rock, sand, bacteria, skimmer, and socks. No fish, corals, or inverts. And lights off.

 

[Timfish]

I use the above mentioned ratio of 50/50 myself. Roughly 2/3 to 3/4 lbs combined total per gallon. I treat live rock (I'm assuming you're getting either maricultured or wild live rock air freight) like corals and QT for a month with appropriate lighting for any corals or other photosynthetic organisms that's on the rock. A minimum I'd want to use in your situation would be 50 lbs combined with your existing rock and additional dry rock.

 

[jda]

This is a very interesting read!!! Would there be any adverse effects to the process if you just do this in your display tank for those months, rather than a Rubbermaid? Obviously having just the rock, sand, bacteria, skimmer, and socks. No fish, corals, or inverts. And lights off.

Off the top of my head... other than needing to resist the temptation to go faster, this would probably work. Initially, the sand, which is likely phosphate free if it was bagged from Caribsea or something near the ocean, will bind some of the phosphate unbound by the rock or from the decaying organics, but if you keep going until the levels are low (like for real), then I think that it all washes out in the end.

In some ways, if you are set up with a skimmer, filter socks, etc., then this might be easier than a makeshift tub.

That temptation to get that awesome Yellow Tang for $40 if/when Hawaii starts to collect again might be pretty hard to overcome, though. I don't know if I could do resist just starting up the tank, but there are many with strong willpower who probably could.

If you quit halfway through, then I feel that you could be worse off since you just transferred some of that phosphate to the sand from the rock instead of removing it.

 

[Miami Reef]

This is a great question because I’m setting up a tank soon.

I bleached all my rocks so I can aquascape them as long as I want without die off. I have about 10 pounds of live rock from KP in my coral QT ready to seed.

Once my tank is home (2 weeks) then I will put the dry rocks in the tank and the live rocks and run my protein skimmer/filter socks/and phosguard. I will ensure phosphates stay around 0.10ppm.

I do not like Lanthanum chloride because it will make phosphate kits show false positives which ruins the accuracy.

 

[bruno3047]

I’ve always used 10-20% of the total rock to be live rock as a guide with as much diversity of coralline colors as possible.

 

[DocRose]

Off the top of my head... other than needing to resist the temptation to go faster, this would probably work. Initially, the sand, which is likely phosphate free if it was bagged from Caribsea or something near the ocean, will bind some of the phosphate unbound by the rock or from the decaying organics, but if you keep going until the levels are low (like for real), then I think that it all washes out in the end.

In some ways, if you are set up with a skimmer, filter socks, etc., then this might be easier than a makeshift tub.

That temptation to get that awesome Yellow Tang for $40 if/when Hawaii starts to collect again might be pretty hard to overcome, though. I don't know if I could do resist just starting up the tank, but there are many with strong willpower who probably could.

If you quit halfway through, then I feel that you could be worse off since you just transferred some of that phosphate to the sand from the rock instead of removing it.

Okay. So they key takeaway for ME from what you're saying is (if possible) don't put the sand into the tank until the rock is finished. I say key for me, because I'm perfectly fine resisting temptation. I still have my 29 gallon setup that I can enjoy while I wait for the rock in my new Reefer 250 to become ready. Cycle the rock for a few months in the reefer, and then when it's done add the sand and enjoy! ;Happy

 

[ReeferSamster]

How much live rock is ideal to seed an otherwise dry rock tank?​

Even a tiny piece is enough. It just depends on how long you are willing to wait.
In the superficial level; yes diversity matters. Yes the qty matters.
But in the grand scheme of things, a few colonies of bacteria is all it takes to spread the fire.

Just make sure you have real live rock that are like sponges.

 

[bruno3047]

OK, I realize I'm likely to get at least 1,000,001 opinions on this, but I'll give some context to the question.

I'm looking to upgrade a 50g tank to a 200+g tank. I'm also looking at starting a small office tank. I've only got the rock that is currently live from the previously set up 50g reef. It's been active for the last 6 years, so there's plenty of good stuff in it.

So, since I'm planning to use mostly dry rock in the big reef and add the previously used live rock to it, I'm wondering if there's a magic ratio that will kick things off well. I'm also considering taking a little of that live rock and adding it to the scape in the smaller office nano to kick that one off to.

I do realize that it's probably a "the more, the better" kinda scenario, but I'm wondering if there's a tipping point (I'm kinda assuming there is). Like what's the minimum to get good results, and then where do diminishing returns start to set in? So I guess I'm looking for a ratio window of sorts...

Does this make sense? If the above is confusing, just ask questions and I'll try to clarify what I'm saying. LOL

Thanks for the help, guys! Excited to have this discussion.

I think what you should probably try to do is get as many different colors of coralline algae as possible. I’ve seen tanks that have that drab red color of coralline and nothing else. Does nothing for me. When I started my tank about four years ago I put something like this into it as the only live rock. The results have been more than satisfactory. Look at all the different colors of coralline on this one rock. Forget about the zoos. I was only after the multicolored coralline. Of course, prices were much cheaper then. I think I paid 40 bucks for my rock. Just some food for thought.

Buy Fish Online: Buy Tropical Fish, WYSIWYG corals, clams and inverts online at the Diver's Den® Store

 

[LRT]

I use the above mentioned ratio of 50/50 myself. Roughly 2/3 to 3/4 lbs combined total per gallon. I treat live rock (I'm assuming you're getting either maricultured or wild live rock air freight) like corals and QT for a month with appropriate lighting for any corals or other photosynthetic organisms that's on the rock. A minimum I'd want to use in your situation would be 50 lbs combined with your existing rock and additional dry rock.

This. I used about a 50/50 ratio of gulf live rock to completely barren/no visible life, walt smith fiji rock i had flown in. Within a year of being in my sump the Walt Smith was nicely seeded with bivalves, sponges, feather dusters and critters etc. I think the more live rock you use the faster dead rock will seed.

 

[bruno3047]

I think what you should probably try to do is get as many different colors of coralline algae as possible. I’ve seen tanks that have that drab red color of coralline and nothing else. Does nothing for me. When I started my tank about four years ago I put something like this into it as the only live rock. The results have been more than satisfactory. Look at all the different colors of coralline on this one rock. Forget about the zoos. I was only after the multicolored coralline. Of course, prices were much cheaper then. I think I paid 40 bucks for my rock. Just some food for thought.

Buy Fish Online: Buy Tropical Fish, WYSIWYG corals, clams and inverts online at the Diver's Den® Store

Just wanted to clarify. I didn’t use this rock as my source of bacteria. I only used it to seed the coralline algae. I first cycled the tank using Bio Spira and Dr. Tim’s ammonia solution. I’ve had numerous issues with pests coming into my previous tanks on live rock. I’ll never use live rock again.

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