Seeding freshly "cooked" dry rock questions

apexkeeper · 01/20/2014, 04:14 PM

So I took all my old dry rock and soaked it in a 10:1 bleach solution for 24 hours, rinsed it thoroughly then soaked it in a 10:1 hydrochloric acid & RO/DI water solution for 4 hours, finally rinsed it again in RO/DI water with prime added to it. So now my rock is as clean and organic free as it can get and I'm ready to seed it with a few pieces of live rock.

My plan is to put all my clean dry rock in a tub with RO/DI salt water with a heater and a few pieces of live rock for seeding but have a couple questions.

1. Do I need to add a light over the tub?
2. Do i need to "ghost feed" or add some dead shrimp etc to the tub to help feed the bacteria?
3. how often should I do water changes on the tub?
4. How do I know when my dry rock is ready to go? wait till the water tests zero for nitrites?
5. Once the process is done is all the rock 100% ready to put in my tank and will it still cause a cycle in the tank?

Thanks!

asylumdown · 01/20/2014, 04:41 PM

if the goal is just to get your rock colonized with nitrifying bacteria, and not all the other things (sponges, pods, algae, worms, etc. etc.) so that it can function as a biological filter, I would add pure ammonium chloride or ammonia until the concentration in your tub is 2ppm, and I'd leave it in the dark. Since you'll also have live rock in there you'll probably have to re-dose every day or two to keep the concentration at the right level while the rest of the rock cycles.

Nitrifying bacteria get their carbon from atmospheric CO2, so as long as there's a source of ammonia and decent circulation, they'll grow.

If your goal is to get the rock colonized with all the other things, skip the ammonia and ghost feed, but I'd still keep the lights out. You'll just encourage nuisance algae to grow, and sterile rock seems much more susceptible to being taken over than rock that's already got layers of more desirable life on it.

The downside to ghost feeding is that it encourages the growth of heterotrophic bacteria that munch on the organic carbon waste, which can lead to a 'false' cycle and outcompete the much slower growing true nitrifiers for space and resources. Also, things like sponges grow slowly and won't start making much of an appearance until your rocks are all back in the tank and set up anyway, and organisms like pods and worms are incredibly resilient and fast to reproduce, so if it were me I wouldn't be as worried about them as the rock's capacity to process nitrogenous waste at the re-seeding phase. So if it were me, I'd go the ammonia/ammonium route and treat it like you would any other cycle. If you keep the concentration at or below 2ppm, it's very likely that a whole bunch of pods and worms will still survive on your seed rock, and their populations should explode once your rock is back in the tank with fish and corals.

Also, make sure there is absolutely nothing on the 'seed' rocks that you don't want on the rest of them. I'd only use rock that I had had for months and was 100% certain was free of bubble algae, aiptasia, etc. If you go pick up fresh pieces of 'seed' rock from the LFS, chances are better than not that you're just going to re-infest your cleaned rocks with whatever it was you were trying to get rid of in the first place.

Finally, I'd do enough water changes to keep the nitrate levels (if you're dosing ammonia) and phosphate levels (if your'e ghost feeding) within acceptable ranges for a tank, which will probably mean very large water changes if there's no other nutrient export going on. The better the quality of the water the rock is in during the re-seeding phase, the less likely you are to have problems later.

asylumdown · 01/20/2014, 04:51 PM

Quote:

Originally Posted by apexkeeper

So I took all my old dry rock and soaked it in a 10:1 bleach solution for 24 hours, rinsed it thoroughly then soaked it in a 10:1 hydrochloric acid & RO/DI water solution for 4 hours, finally rinsed it again in RO/DI water with prime added to it. So now my rock is as clean and organic free as it can get and I'm ready to seed it with a few pieces of live rock.

My plan is to put all my clean dry rock in a tub with RO/DI salt water with a heater and a few pieces of live rock for seeding but have a couple questions.

1. Do I need to add a light over the tub?
2. Do i need to "ghost feed" or add some dead shrimp etc to the tub to help feed the bacteria?
3. how often should I do water changes on the tub?
4. How do I know when my dry rock is ready to go? wait till the water tests zero for nitrites?
5. Once the process is done is all the rock 100% ready to put in my tank and will it still cause a cycle in the tank?

Thanks!

Sorry I didn't really answer 4 and 5.

You'll know it's ready when you dose enough ammonia to bring the water to 2ppm, and it shows zero ammonia and zero nitrite within 12-24 hours. If you're rotting a shrimp or ghost feeding, you'll know it's ready once the ammonia and nitrite levels have fallen to zero.

And no, if you've properly cycled it in the tub, there won't be a cycle later. I suspect there might be some instability for a month or two if you used ghost feeding or rotting shrimp as populations of heterotrophs crash/re-organize to the dominant carbon regime in their new home, but you shouldn't see a classic 'cycle' either way.

apexkeeper · 01/20/2014, 07:24 PM

Thanks for the info! I'm only trying to seed bacteria so I'll go with the ammonia route. All my pods and beneficial critters will come when I add cheato to my fuge anyway. I'm getting my seed rock from a friends tank that has been running for a couple years and "SHOULD" be free of any harmful organisms like aiptasia etc.

01/20/2014, 04:14 PM	#1
apexkeeper Registered Member Join Date: Dec 2013 Location: Central, NJ Posts: 297	Seeding freshly "cooked" dry rock questions So I took all my old dry rock and soaked it in a 10:1 bleach solution for 24 hours, rinsed it thoroughly then soaked it in a 10:1 hydrochloric acid & RO/DI water solution for 4 hours, finally rinsed it again in RO/DI water with prime added to it. So now my rock is as clean and organic free as it can get and I'm ready to seed it with a few pieces of live rock. My plan is to put all my clean dry rock in a tub with RO/DI salt water with a heater and a few pieces of live rock for seeding but have a couple questions. 1. Do I need to add a light over the tub? 2. Do i need to "ghost feed" or add some dead shrimp etc to the tub to help feed the bacteria? 3. how often should I do water changes on the tub? 4. How do I know when my dry rock is ready to go? wait till the water tests zero for nitrites? 5. Once the process is done is all the rock 100% ready to put in my tank and will it still cause a cycle in the tank? Thanks!

01/20/2014, 04:41 PM	#2
asylumdown Registered Member Join Date: Dec 2009 Posts: 437 Blog Entries: 5	if the goal is just to get your rock colonized with nitrifying bacteria, and not all the other things (sponges, pods, algae, worms, etc. etc.) so that it can function as a biological filter, I would add pure ammonium chloride or ammonia until the concentration in your tub is 2ppm, and I'd leave it in the dark. Since you'll also have live rock in there you'll probably have to re-dose every day or two to keep the concentration at the right level while the rest of the rock cycles. Nitrifying bacteria get their carbon from atmospheric CO2, so as long as there's a source of ammonia and decent circulation, they'll grow. If your goal is to get the rock colonized with all the other things, skip the ammonia and ghost feed, but I'd still keep the lights out. You'll just encourage nuisance algae to grow, and sterile rock seems much more susceptible to being taken over than rock that's already got layers of more desirable life on it. The downside to ghost feeding is that it encourages the growth of heterotrophic bacteria that munch on the organic carbon waste, which can lead to a 'false' cycle and outcompete the much slower growing true nitrifiers for space and resources. Also, things like sponges grow slowly and won't start making much of an appearance until your rocks are all back in the tank and set up anyway, and organisms like pods and worms are incredibly resilient and fast to reproduce, so if it were me I wouldn't be as worried about them as the rock's capacity to process nitrogenous waste at the re-seeding phase. So if it were me, I'd go the ammonia/ammonium route and treat it like you would any other cycle. If you keep the concentration at or below 2ppm, it's very likely that a whole bunch of pods and worms will still survive on your seed rock, and their populations should explode once your rock is back in the tank with fish and corals. Also, make sure there is absolutely nothing on the 'seed' rocks that you don't want on the rest of them. I'd only use rock that I had had for months and was 100% certain was free of bubble algae, aiptasia, etc. If you go pick up fresh pieces of 'seed' rock from the LFS, chances are better than not that you're just going to re-infest your cleaned rocks with whatever it was you were trying to get rid of in the first place. Finally, I'd do enough water changes to keep the nitrate levels (if you're dosing ammonia) and phosphate levels (if your'e ghost feeding) within acceptable ranges for a tank, which will probably mean very large water changes if there's no other nutrient export going on. The better the quality of the water the rock is in during the re-seeding phase, the less likely you are to have problems later.

01/20/2014, 07:24 PM	#4
apexkeeper Registered Member Join Date: Dec 2013 Location: Central, NJ Posts: 297	Thanks for the info! I'm only trying to seed bacteria so I'll go with the ammonia route. All my pods and beneficial critters will come when I add cheato to my fuge anyway. I'm getting my seed rock from a friends tank that has been running for a couple years and "SHOULD" be free of any harmful organisms like aiptasia etc.