Marco rock vs Dry Reef rock - Advice needed

[Tanksy]

Hi all,

I'm setting up my nano reef tank and I'm going to need 5-7 kg of rock.
On one hand, I like the practicality of Marco rocks. Easy to aquascape. Just a rinse and I'm good to start cycling my tank. However, it's just limestone and the cycle will probably take longer..
On the other hand, dry reef rock (i.e Pukani, Fiji, etc) is more porous, meaning more space for bacteria. But I'd have to cure it first before starting the cycling process, and even after curing it, there's a possibility of PO4 leaching.
I'm torn!

I'd appreciate if anyone with advice or experience with either or both, could post here.

Cheers!

[natalia_la_loca]

I used dry Marco rock in my 7-year old reefbowl, some of it was repurposed from my old Nuvo 8. I haven’t had any problems that I could clearly attribute to the rock.

[banasophia]

I really love Caribsea Liferock myself… I’ve used it in 4 of my 5 nano tanks, Marco rock in the other tank… for one tank it was wet/cured from my LFS… for the other 3 tanks it was dry… best if you can get it already cured, but dry is fine… I always add some Biospira  for the cycle and some Seachem Matrix media to my back chambers of my tanks to increase surface area for the beneficial bacteria since the rock seems a bit dense to me. I like the coating because it looks nice from the get go, masks some of ”the uglies” and seems somewhat resistant to algae growth. 

[natalia_la_loca]

Wanted to add that in my Evo 13.5 I’m using a combo of Caribsea Liferock, Marco Rock and dry reef rock pre-cured by my LFS. Also working out very well. Imo as long as you cycle it properly and are proactive about managing any nuisance algae/critters that come in on frags, it mostly comes down to your goals for aesthetics and biodiversity.

[Tanksy]

Thank you for your replies!

 

I went to a couple of lfs to check out the two types of rock.
Whilst Marco rock is sterile, and safe to throw it right away in a DT, it looks like limestone.
So, I bought only 1 kg of Marco rock, to use it as a base and 5 kg of dry reef rock (don't know if it's Pukani or Fiji) for the aquascape.

Well, it wasn't exactly dry, as it was in a tub of water, but without circulation or heating.

 

I'll leave it for a couple of days to dry in the sun, wash it with the hose and remove dead sponges, algae, etc.

Then I'll put it in SW with a powerhead and a heater for 2-3 days and test for phosphate. A 20 l bucket will do. After that:

1 week in bleach and RO water to break down any organic matter in the rock, changing water every day.
2 days to let it dry in the sun and another 2-3 days in RO water with dechlorinator (just to be safe).
2-3 days in SW to test again. If PO4 is still high, then I'll probably add some Rowaphos for as long as necessary.
My plan is to have a PO4 reading between 0.05 and 0.1 ppm.

[banasophia]

If it was in a vat of saltwater at the LFS why would you be drying it out? 

[mcarroll]

1 hour ago, Tanksy said:

I'll leave it for a couple of days to dry in the sun, wash it with the hose and remove dead sponges, algae, etc.

That's harsh if it was live at all....would have been better to run it in a tank of saltwater with a skimmer for a while, maybe with some water changes.

 

Keep it alive, IMO.

 

Dead rock is the MOST susceptible to pests like green algae.  

 

1 hour ago, Tanksy said:

Then I'll put it in SW with a powerhead and a heater for 2-3 days and test for phosphate.

You're slightly obsessed with phosphate levels and this rock....even before you had it.  Itchy trigger finger. 😉 

 

I'm almost convinced that this "PO4 leaching issue" was manufactured just to freak out newbs.  It doesn't make any sense if you thing about it much.

 

If your rock is dirty, it will usually be apparent to your eyeballs.  Scrub off the dirt/dead stuff, and then start curing it.  Don't kill it!   🙂 🙂 🙂 

 

You can even start curing it "dirty" and just add some hermit crabs in to scavenge off the unwanted bits.  It's what they do.

 

It's best if there's no light until it's clean and cured.

 

1 hour ago, Tanksy said:

My plan is to have a PO4 reading between 0.05 and 0.1 ppm.

You gotta see if this is even an issue first, right??

 

Second, there's nothing wrong with even higher levels of PO4 than you mentioned.  Way higher.  Especially when you're getting your rock started.....TONS of beneficial stuff is going to growing and spreading if you allow it. That "reserve" of PO4 will be used up quickly.

 

Sounds like this rock would benefit from seeding with some substrate from a seasoned tank, or something like that.

 

If you're going through all this due to algae paranoia, then IMO you have to take a different route in your thinking.  Algae blooms aren't caused (or prevented) by phosphates.

 

All you're doing currently is hamstringing your rock and making an algae bloom a bit more likely and giving it more potential real estate that's ready to dominate.

 

In the photos that rock actually looks fine.  At least get your first round of tests in before you decide what to do.   You're better off assuming the best case until you know different.

 

 

[Tanksy]

1 hour ago, banasophia said:

If it was in a vat of saltwater at the LFS why would you be drying it out? 

It was tap water, not SW.

[mcarroll]

Just now, Tanksy said:

It was tap water, not SW.

I would still start off curing assuming the best case scenario, not worst.   "going nuclear" like you were planning is practically never called for.  👍

[Tanksy]

Hey @mcarroll!

Whatever was alive on that rock is long dead, as it's been sitting in tap water for months. 

I did think of just cycling it as it is. All the nutrients from the decomposing material would be a booster for bacteria, but on second thought, I'd rather kick this off with a clean slate. The rock had been used in coral tanks, so there's a chance of low levels of PO4. Obviously I couldn't possibly know without testing it first. 

It's always good to have a plan B, right?

[Lebowski_]

Should be fine, but prepare yourself for the uglys.

 

If I were you, I would consider getting some Microbacter7 ready, and some 3% hydrogen peroxide also just in case.

 

Watch closely for the first 4-6 months, make sure your nitrates and phosphates don't 0 out. Reef roids is great for boosting phosphates. Try to get some live rock to seed it.

 

Oh, if you use Fritz9000 or Dr Tim's 1 and only, the macro won't take longer to cycle. You just gotta keep feeding the tank carbon and ammonia sources. The downside is that you will have a pretty limited bacteria population, which allows other less friendly things to move in, however, nitrifying bacteria won't be an issue.

 

 

[Tanksy]

9 hours ago, Lebowski_ said:

Should be fine, but prepare yourself for the uglys.

 

If I were you, I would consider getting some Microbacter7 ready, and some 3% hydrogen peroxide also just in case.

 

Watch closely for the first 4-6 months, make sure your nitrates and phosphates don't 0 out. Reef roids is great for boosting phosphates. Try to get some live rock to seed it.

 

Oh, if you use Fritz9000 or Dr Tim's 1 and only, the macro won't take longer to cycle. You just gotta keep feeding the tank carbon and ammonia sources. The downside is that you will have a pretty limited bacteria population, which allows other less friendly things to move in, however, nitrifying bacteria won't be an issue.

 

 

Yes, I'll definitely add some live rock rubble in the sump in the early stages of the cycle.

[Tanksy]

Hi all,

The rock is in a bucket full of tap water and thin bleach at the moment. Almost all guides say that it should be left in the solution for a week.
However, when mixed with water, bleach breaks down to oxygen and saltwater in 24 hours. That means the solution is effective for only 1 day. 
So, here's my questions:
1. Why leave it in the solution for a week? The rock would be sitting in saltwater for 6 out of 7 days.
2. Should I renew the solution, if not every day, at least every other day?

Cheers!

[mcarroll]

Curing rock in bleach is very 1980's.