Adding dry rock to an already established tank

[fishman7789]

I have a 72 bowfront with about 65 pounds of live rock in it that has been setup a little over 3 months now. I'm beginning to think I'd like to add a few more pieces of Rock to fill out the tank a little more. Does anyone see a problem with adding 25 lbs of DRY Marco rock to an established tank? Would it be safe to do it all at once? I know the rock is dry and technically should be safe to add without the risk of starting a cycle. Just wanted to get some people's opinions
Was also considering letting the dry rock sit in a couple buckets with heaters and powerheads for a week or two just to be safe

 

[thirty6]

if makes you feel better you can let sit in buckets but its not needed. just give a rinse with some ro water and add it in. i

 

[fishman7789]

Ok cool. That's what I figured considering it is dry rock just wanted to be 100%

 

[marrone]

Dry Marco rock needs to be cured before you place it into your tank. It may cause a cycle in your tank, especially since you're going to be adding a good amount to the tank. I would let it sit in a bucket, with a power head, for a couple of weeks until it cycles.

Also, Marco rock is know for phosphate leaching, so you want to get rid of the phosphates before placing the rock into your tank.

 

[E.intheC]

How would dry rock cause a cycle? I understand how it causes phosphate levels to rise, but not cause the nitrogen cycle to happen again...

 

[marrone]

You'll find that most of Marco Dry rock has plant and other organic material on it or inside of it, which when placed in a tank will cause ammonia to come off it. You need to realize that it's just not dry rock, or even bleached white/blue coral that is completely sterile. It was once all live so there will be remains that will break down in the tank. Now, it will be no where near as what you would get with Live Rock, which can have a lot of live and organic material on it, which can and usually will die off. The big thing about Dry rock is you don't get all of the hick hikers that you get will live rock.

 

[albano]

You'll find that most of Marco Dry rock has plant and other organic material on it or inside of it, which when placed in a tank will cause ammonia to come off it. You need to realize that it's just not dry rock, or even bleached white/blue coral that is completely sterile. It was once all live so there will be remains that will break down in the tank.

+1...Marco rock must be cured

 

[fishman7789]

How long would you suggest curing it for in buckets? Should 2 weeks be sufficient?Also the rock is sold as "cured" dry rock but who knows If there is any truth to that statement? I am definitely going to let it sit in a bucket for a period of time just unsure of how long. What do you guys think?

 

[skene]

You would let it sit... and cure then cycle... just as you would a regular tank.

 

[isnyc300]

I added about 50 pounds to my tank and I let it cure for about 3 weeks

 

[KathyC]

How long would you suggest curing it for in buckets? Should 2 weeks be sufficient?Also the rock is sold as "cured" dry rock but who knows If there is any truth to that statement? I am definitely going to let it sit in a bucket for a period of time just unsure of how long. What do you guys think?

There is no such thing as cured dry rock. (Curing being another word for 'cycled') If it is dry it cannot be considered 'cycled'.

Just letting it sit in a bucket will give you wet rock, not cured rock.

You need to add a piece of cured live rock to begin to populate the marco rock with bacteria and after a few weeks it will be live and you can safely add it into the tank.
And I would definitely test the phosphate levels before adding the rock to your tank!

Hate to be a nit-picker (I have my moments...) but a tank that is 3 months old would not be considered an 'established' tank. You easily need to give a tank a year to consdier it close to being established. It means the tank has enough life in the rocks alone -and taking your bioload into consideration - to not be seeing any swings in the parameters as the live rock is sufficiently alive with bacteria to balance out the output of the fish (ammonia-wise) and what food you are adding to the tank.
You want to see longer range stablility in a tank before considering it eastablished
At 3 months old, you are nearing the end of your algae cycles.

PS I haven't forgotten about those frags..I will get them over to you!

 

[fishman7789]

Ok thanks Kathy that was going to be my next question if I should add an existing piece of live rock when cycling the base rock to help seed it.I actually have a spare 20h tank laying around I'll probably just place the dry rock in there with a piece or two of my live rock and use some water from a water change to fill it and let it all sit in there for 3-4 weeks
Thanks for all the help. I'll gladly take some of those frags off your hands when you're ready to part with them

 

[duke62]

add a little at a time first like 5 lbs at a time and you will be fine. i do it all the time when adding branch rock. i do boil it for 1/2 hour before each piece goes in and never had a issue. i have 100 twv though

 

[E.intheC]

There is no such thing as cured dry rock. (Curing being another word for 'cycled') If it is dry it cannot be considered 'cycled'.

Just letting it sit in a bucket will give you wet rock, not cured rock.

I agree. Except, putting dry rock in a bucket of RO/DI water will cause the phosphates in the rock to leach out. Doing water changes will then reduce the levels of phosphate in the rock. (And that's a good thing).

 

[Awibrandy]

You have already been given great advice by Marrone & KathyC, I would just like to add: Test the water regularly, and you will have the answer as to when it is safe for you to add the new rock to your tank.
Things work differently for everyone my friend. For instance I have personally added dry tonga rocks to my tank with no issues, but my DT is a 155 gallon tank, and I only added like 10 or 15lbs at a time. I have no knowledge on Marco rocks except for what I have read, and I rather speak from personal experience.

 

[fishman7789]

thanks for all the help guys (and Girls) lol. the rock came today and i must admit there are some very nice looking pieces and i was shocked at how much rock there was in a #25 box. my only complaint about it is that it almost looks man made. the rock is so clean and there are absolutely no signs of dead organic matter on it which isn't necesarilly a bad thing. i must say though i did give it a quick dip in r/o water today before i had to run to work and it did cloud the water pretty quickly.
i will be taking everyones advice and curing/cycling the rock. tomorrow i am going to pick up a tote from home depot and place the rock in there along with some water i will take out of my tank during tomorrows water change. i will leave it covered in the tote with a powerhead and heater for a few days and test for phosphate daily. if the phosphate levels read 0 after a few days i plan on taking some rubble rock from my tank and adding in to the bin to seed the rock. i will probably let it sit like that for 3-4 weeks and test all the levels periodically.

 

[duke62]

since you are going to cure it i wouldnt use any tote from HD none of them are food grade and can leach toxins into the rock. i would suggest going to ace and get a brute garbage can

 

[fishman7789]

yea i am actually going to pick up to brute garbage cans tomorrow because along with the base rock that came today my bulk reef supply rodi unit and portable tds meter came today :smile: . i was planning on using one to store rodi water and the other one for pre mixed saltwater. at about $27 a piece for the 32 gallon cans i really don't want to buy 3. my question is if i buy the 2 cans and use one of them to cycle the rock in would it be safe to use that trash bin after i cycled the rock as a storage for saltwater?

 

[Awibrandy]

I would just rinse the heck out of it, and then you can use it for either fresh ro/di or pre-mix water.