Why not a chunk of limestone in the sump?

[Tom Wood]

Just curious,

90 gallon, CO2 injected, 2WPG.

Our water has about 180ppm total hardness. I'm down to a 20% water change once every two weeks, weekly testing/dosing of NO3 and PO4, and weekly dosing of K+ and traces. Big prune once a month or longer.

I refuse to bother with Ca and Mg testing or dosing. For a tank where I just want green plants with no special needs, can I just put a chunk of limestone in the sump and be done with it? Would that also address most traces? I'm trying to lengthen the time between -any- maintenance efforts.

TIA

TW

 

[chubasco]

Re: Why not a chunk of limestone in the sump?

That would definitely address the hardness of water on the Ca side. Doubt
if it would help any on the traces, depending on what else might be in the
limestone. Interesting to see what the rate of dissolution is in a chunk of
limestone. TW, have you gone to a wet/dry system for your tanks or is this
for changewater holding tanks? Yeah, 10 degrees total hardness is a little
light, but looking at the pic of your 90 gallon, seems to be adequate(?)
What size of limestone are you gonna place in the sump: golfball, hardball,
softball, beachball ? With a little current in the sump, that would help
dissolve the CaCO3 a little faster than the chip I placed in a glass of water
one time And is this storebought limestone or are you mining your own?


Bill

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

Hey Bill,

This is the same 90 in that pic. There is an in-tank sump on one end that the water overflows into. A submersible pump takes the CO2 injection and then returns the water to the main part of the tank. I put a chunk of limestone in the sump today, and I'm just curious as to what to expect.

I haven't been adding anything else to affect GH except water changes, which I want to minimize now to one 20% change every two weeks. So I'm thinking the limestone might even out the Ca, Mg and any possible traces. I'll still dose CSM+B, but I suspect there's traces in the limestone too.

TW

 

[chubasco]

Re: Why not a chunk of limestone in the sump?

Good luck, TW,
I think limestone is purty much just CaCO3, tho. Neat idea about the sump/CO2 injection, too!

Bill

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

I remember getting a chemical analysis of the limestone from a local quarry way back when. It included a long list of 'stuff' but I don't remember it all. Seems like rock in the ground would be less than pure anything.

TW

 

[travdawg]

Re: Why not a chunk of limestone in the sump?

What pic? lol I am trying to eyeball every 90 gallon I can for when its time to plant mine!

 

[Ian H]

Re: Why not a chunk of limestone in the sump?

How about using dolomite limestone? That has a level of Mg in it. I'm thinking about adding some to my tank as my Gh reading is only 7 degrees.

Ian

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

What pic? lol I am trying to eyeball every 90 gallon I can for when its time to plant mine!

Here:

http://www.barrreport.com/gallery/showimage.php?i=66&c=3&cutoffdate=all

This is an unusual setup though, I have black eggcrate on the back and sides for the h. difformis.

TW

 

[Ian H]

Re: Why not a chunk of limestone in the sump?

Sorry to go off topic here, but what is eggcrate please?

Ian

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

Sorry to go off topic here, but what is eggcrate please?

Ian

Some flourescent light fixtures in office buildings use a sheet of white eggcrate as a diffuser. It's a grid of plastic with 1/2" square openings and is about 3/8" thick. It's also available in black plastic from plastic suppliers.

TW

 

[Ian H]

Re: Why not a chunk of limestone in the sump?

Some flourescent light fixtures in office buildings use a sheet of white eggcrate as a diffuser. It's a grid of plastic with 1/2" square openings and is about 3/8" thick. It's also available in black plastic from plastic suppliers.

TW

OIC. So do you use it like trellis to train the unruly plants?

Ian

 

[chubasco]

Re: Why not a chunk of limestone in the sump?

The white eggcrate is at both Lowes and Home Depot but you can get the
black stuff at specialty lighting places, too. The black is 1/2" square and the
white is 5/8" square in my area.

Yes, Ian, a trellis, pretty neat idea, too. I'm getting more of the black eggcrate

Ian, about the dolomite...do you have to check with the Italian authorities
before you go chipping away at their mountain range in northern Italy?
Curious... Wonder if all dolomite has magnesium or is it
peculiar to certain areas?

Bill

 

[Ian H]

Re: Why not a chunk of limestone in the sump?

Bill, I think that all limestone sold as dolomitic lime contains magnesium. And no I will get it from my local garden centre not from the Dolomites.

Ian

 

[fishface]

Re: Why not a chunk of limestone in the sump?

so what is the desired level of gh by the way??

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

OIC. So do you use it like trellis to train the unruly plants?

Ian

When my plants get unruly, I just smack them.

Actually, the eggcrate is held off the tank and sides by a small piece of eggcrate about an inch wide (two squares) so there is room between the back side of the eggcrate and the inside surface of the aquarium. Then I just stick the bottoms of the h. difformis into the eggcrate and let it grow. Once it gets too big, I pull it out of the eggcrate, pinch off the bottoms of the plants, and replant into the eggcrate.

TW

 

[defdac]

Re: Why not a chunk of limestone in the sump?

My experience with coral-crush and limestone in the filter is that the GH slowly increases over time until next water change where it dip down again.

This unstable GH seem to stunt growth. I don't know if it's due to constant aclimatization problems or if the calcium hydroxide removes all the phosphate:
http://scifun.chem.wisc.edu/CHEMWEEK/Lime/lime.html

 

[Tom Barr]

Re: Why not a chunk of limestone in the sump?

It'll take a long time to dissolve, and not have as much effect vs a bag of dolomite.

You could add some SeaChem EQ, that has everything you want.

Regards,
Tom Barr

 

[Tom Wood]

Re: Why not a chunk of limestone in the sump?

Not much effect is probably what I want though. I refuse to add a 'product'.

Thanks defdac for that link. I'll keep an eye on the PO4.

Earlier in the day I'd dosed K2SO4, then added the chunk of limestone. Got a lot of debris (precipitate?) in the water. This morning it's mostly clear.

TW

 

[Tom Barr]

And now for the rest of the story..........

Then use CaCl2 and Mg SO4 and be done with it. Both are cheap.
10lbs of CaCl2 will last years and years. Most pool places sell it.

From the article: "because lime is highly alkaline"

The PO4-Ca issue is only an issue when you have certain conditions(higher pH's). That's why they add the lime in the first place. PO4 in tap water is not an issue for most, it is the Ca and hardwater issues for consumers.

Some rich PO4 waste waters need NH4/NO3 and PO4 removal as well as salt removal before dumping it into the environment.

This goes up to near a pH of 10.1 and is used for lime softening of tap waters.
Ca preciptates out at these pH's, not just PO4.

Might want to add that tidbit when you believe the PO4 is declining in your planted tank with it's far lower pH's.

Tom, you can add aragonite or dolomite to a tumbler, any device that tumbles sand/gravel around with flow going past it if you want to increased the dissolving rate. Also, any CO2 reactor tube can suffice as such.

Regards,
Tom Barr