Is Lime Rock bad as a base rock for reef tank?

[saintperez]

I've had my tank setup since 2008. Never really did a great job at husbandry. Now I've reset it up. Got the LEDs, the Calcium Reactor, doing water changes very frequently (was my biggest problem), checking my parameters religiously. Goal is to setup an SPS tank.

When I setup the tank I laid some big pieces of lime rock I got cheap from a local LFS as my base rock. Will this have any ill effects for my SPS plans?

 

[Reefkeepr1986]

Limestone,"Live rock" is all made up of calcium carbonate which all have phosphates!! Just be sure to cure them before adding them to your system and test to be sure the Limestone isn't leaching Excess phosphates in your new tank!! Honestly I don't use the rock limestone, but if I were you, I would just spend the money on good deals Of other reefers selling Liverock online like CL trust me if your wanting to Have an SPS tank your Corals are going to Prized corals and it may just save you money and BAD headache later!! If this setup your saying is SPS corals I wouldn't go cheap on equipment,supplements, and especially Live rock because your corals will depend on your rocks to help keep your system at Equilibrium as far as Natural water buffer,and micro organism housing!! So IMO just look online and see if there are anybody selling their rock for cheep?? That's how I got all my rock!! I'm literally a Liverock hoarder!!
LoL

 

[Randy Holmes-Farley]

Some limestone may have substantial phosphate in it, but not all does. It really depends on the source.

As mentioned, you can also try to extract the surface phosphate from rock. For example, an acid rinse, or soaking in water with a binding chemical in it, such as lanthanum chloride or GFO.

Once in the tank, the thing to do is keep an eye on phosphate.

If it is base rock that isn't exposed to light, I don't think the issues will be large and can be dealt with by phosphate export, if needed.

Remember, every feeding brings in massive amounts of phosphate, so you need phosphate export anyway.

The problem comes more if the rock is exposed to light, and algae may grow on the rock, extracting phosphate locally that is hard to always remove by treating the tank water.

 

[saintperez]

Thank you Randy. As mentioned The tank has been setup with the rock in there since 2008 although I don't remember my previous Phosphate readings. They are two massive pieces of rock that were nerve wrecking to put in standing on a latter as the top rim of the tank is about 72+ inches off the ground. So you could understand my hesitation to take them out. One of the rocks is very much exposed to light. Recently I re-established the tank, did two successive water changes 50% back to back within a week BUT I used RO/DI that had hold filter elements! I checked my Phosphate and I was at .5ppm! SO I did another 50% water change yesterday using NSW from High Tide at an inlet. Also running GFO although I probably need to change it since I was using the bad RO/DI water. Will do my testing this morning and then put in the new GFO. Anything else I should be doing to bring my Phosphates down? I guess I want to make sure that I'm doing everything possible to keep them low to determine if limestone is leaking phosphates.

 

[Randy Holmes-Farley]

Oh, I thought these were new pieces being added in the reset. I'd look to treat the water with lanthanum chloride or GFO to keep the phosphate lower for a while.

Water changes are not the best way since even a 100% change won't remove what is attached to the rock and some will come off back into the new water.

 

[saintperez]

Thanks Randy, went and got the lanthanum chloride after reading some people with positive experiences with it. Now two questions:
1.) Do you have any good reference for proper dosing amount for my tank?
2.) Is the 10 Micron sock bag really necessary or will a felt bag do?

Thanks,
Santiago

 

[Randy Holmes-Farley]

Generally, it isn't something I recommend in an operating reef tank, and I don't have a dose, but it would be best to add it upstream of some sort of mechanical filtration like a sock to catch the solids that form. Not sure exactly what a felt filter looks like, but as long as it catches the solids, that will probably work.

Watch the alkalinity as it will likely lower it.

 

[SantaMonicaHelp]

That's quite the collection of rocks you got reefkeepr1986 :bigsmile:

 

[Rausch]

When setting up my first tank i wanted to use lime rock as well, since it was very easy to get. After asking local reefers Was told DO NOT DO IT!! Ended up paying a lot more for rock then i wanted but in the long run had no issues with leeching anything into the system! I was told there are a few things not to skimp on when setting up a full mixed reef tank and that was, Water, Lighting, Flow, Live rock. Havnt regretted it since.

 

[saintperez]

I'm starting to think the limestone might be the culprit with my Phosphates issues. have dosed the Lathanum Chloride for 4 times now and was able to bring Po4 down from .79 (I was in shock too) to .30. But just checked again and saw it crept up to 3.5. I turned off the GFO reactor because realized I don't have new so I was afraid the one I had running for a month would be leaking back into the tank. I did a 30% water change Saturday evening and will do another by tomorrow. I don't know if I'm just too impatient but I thought from Lathanum was the super Phosphate killer. Not sure if I should go and get the GFO tomorrow and run both. But overall I'm starting to suspect the Po4 latched unto the rocks during the couple of years the tank was running unattended with only 3-4 water changes a year if that and running old elements on the RO/DI. I've read that old rocks can leak out Po4 at a later point.

Any advice is greatly appreciated.

 

[Randy Holmes-Farley]

It is certainly possible that old rock is holding a lot of phosphate. The lanthanum will be the cheapest approach.

 

[saintperez]

Randy, currently I'm dosing the Lathanum through a very slow drip, maybe 1 drop / 2sec from an IV into a 10 Micron filter sock. Couple of things come to mind:
1. long term dosing of Lathanum, any ill effects from dosing at this rate.
2. Combining Lathanum into my ATO with Kalk for ongoing maintenance of PO4 levels.

Thoughts on these?

 

[saintperez]

Anyone else know?

 

[SantaMonica]

1. Good question, as regarding LC directly on corals. People experienced with dosing LC for many years would need to comment.

Indirectly, you could remove too much P, as some ULNS do. This would stress the corals, causing bleaching.

2. Combining LC and kalk sounds like a Randy question to me

 

[Randy Holmes-Farley]

I've heard of undesirable effects of lanthanum in a few cases, and I'm not a fan of it in general since much of it remains in the tank and it depletes alkalinity. However, it is cheap.

I'd personally avoid it for chronic use, but I cannot prove it is going to cause a problem.

I do not think you can mix lanthanum into limewater as you'll likely precipitate lanthanum oxide/hydroxide and deplete the alkalinity in it.

 

[saintperez]

After dropping my PO4 down from .79 to .04 using Lathanum Chloride, now I'm back to 1.1 after a couple of weeks. Used some MECOral GFO in the meantime that was given to me but not enough in a BRS GFO/Carbon reactor, didn't put a dent. Don't want to keep using the Lathanum as it's putting a slight cloudy film on my glass. Dosed Lathanum yesterday but don't want to touch it again for a while.

Also started dosing Vodka on Monday. I've heard also that PO4 can leak from rocks and sand which is what I suspect is happening. I feed fairly light and have all new elements in my RO/DI that I got about a month ago. Been using Instant Ocean and Reef Crystals (Stopping that and going back to NSW on next change). Been doing water changes every week anywhere from 30% to 50%.

Skimmer running 24/7. Have some Cheato in the fuge but hasn't grown much , probably due to the light. Took out all the rock from my fuge last night, about 5 gallon bucket of rocks.

Really don't want to start taking apart aquascape and removing rocks from DT. ANy other options you guys think I could try? Algae Scrubbers? Better Cheato growth? Bio Pellets?

 

[RacingTiger03]

I would be cautious about the vodka dosing with a phosphate problem. Vodka may cause problems with cyano, and a phosphate leak isn't going to help that situation. Try out vinegar, but primarily carbon dosing helps keep nitrates down, and only moderately helps with phosphates. I'm sure randy will chime in with a more definitive answer for you, though.

 

[saintperez]

I would be cautious about the vodka dosing with a phosphate problem. Vodka may cause problems with cyano, and a phosphate leak isn't going to help that situation. Try out vinegar, but primarily carbon dosing helps keep nitrates down, and only moderately helps with phosphates. I'm sure randy will chime in with a more definitive answer for you, though.

Thanks, according to this article Vodka Dosing by 'Genetics' and 'Stony_Corals' - Reefkeeping.com VOdka dosing helps with PO4 export.

 

[Randy Holmes-Farley]

Thanks, according to this article Vodka Dosing by 'Genetics' and 'Stony_Corals' - Reefkeeping.com VOdka dosing helps with PO4 export.

It does, since any bacterial growth takes up phosphate to make biomolecules such as DNA and phospholipids, but some bacteria use even proportionally more nitrate than the amount of N and P in the bacterial tissues would suggest because bacteria in low oxygen regions of sand and rock can use nitrate as a source of oxygen, not just a source of N for tissues.

That is presumably why many people find that when using organic carbon alone, the nitrate can be depleted, leaving phosphate remaining. Some of us, such as myself, use GFO along with organic carbon dosing for that reason (at least in part).