Using oyster shells to increase hardness and PH.

[fishygurl]

I finally got the PH tested at the LFS today, and the hardness is only .5! Thats why my Ph has been fluctuating so much! So, i was going to raise it using crushed coral, but the smallest bag they have is 10 pounds and that was 20 bucks, so the guy there suggested that i put a shell in the tank. I have these shells that were bleached 3 years ago, and i boiled it just now, it has been outside for 3 years so it should be pretty safe I think... Will this work for raising the hardness?

 

[greenmaji]

DKh? KH? ppm?
CC are used.. baking soda..
travis has a mix I cant remember right off hand..

I dont think I would just boil it.. how about putting it in a bucket of over declorinated water over night?

 

[Wizzard~Of~Ozz]

Yeah, I'ld add a bit of baking soda, (Calcium Carbonate) That will bring up your hardness a bit, ideally you'ld want it at 3 minimum (53ppm). 1 teaspoon (5ml) should get you right around there if my guesstimate is correct. (1ml/4.2Gal)

Math: (included incase I made a booboo)
1Gal = 4546 millilitres
4546 / 1000000 = .004546 (1 PPM)
.004546 * 53 = .24 ml/Gal

 

[BillD]

Is this the same water the LFS is using? If that is the case, and the fish do okay there, perhaps you may want to leave well enough alone. If you adjust your water, you will have to do it for every water change. Most fish are adaptable and it is better to have stable parameters, rather than perfect ones.

 

[jsoong]

The KH being so low need some buffer to maintain pH. This is the one time when doctoring the water is warrented, even for newbies.

Baking soda (actually calcium bicarbonate) will work to rise the KH, but it won't keep a stable pH unless you keep adding the stuff as it is used up. cc being calcium carbonate, will dissolve slowly & maintaine a stable level without much monitoring or work.

FAIK, oyster shells work just as well as cc. But you need to break it into little bits to ensure rapid solution. You'll need a few cups of the stuff and replace as it is being used up, so I don't know if all that work is worth the $20 saving.

 

[fishygurl]

But oyster shells contain calcium carbonate. Im pretty sure of that.

 

[Lonewolfblue]

But oyster shells contain calcium carbonate. Im pretty sure of that.

Yes, but eventually gets used up. Also have to break it up into small pieces as well, so it can release the calcium carbonate better.

 

[fishygurl]

Well i have tons of them so when the ph starts to go down i just add another one.

 

[Lonewolfblue]

Eventually, yes. But not sure how long that would be. You'd think it would last a while. Anyone know how long it would last before having to replace?

 

[Wizzard~Of~Ozz]

Yes, but the speed they are dissolved at can cause it to take too long to make a change.

jsoong, thanks for noticing that mistake.

Eggshells are 95% calcium carbonate. I imagine most shells are made of the same.

 

[Fishyfanatic]

I wouldn't use baking soda. A small mistake can turn into HUGE problems. Plus, you have to keep dosing. Crushed Coral just gets put in the tank and replaced about every 6 months or so. It's gradual and won't cause a pH shock.

 

[fishygurl]

Well i just crushed up a shell and put it in the filter, I only used one because i only want to raise the hardness a little, and i dont want the ph above 7 (its 6.6 now) It was really easy actually i just whacked it with a hammer then dumped it in the filter. (actually if was kinda fun to smash it. LOL I love smashing things! ) Ill just have to see if it works...

 

[jsoong]

Oyster shells are Ca carbonates. I would imagine that almost any shells can be used.

Fishygurl, putting in just a little bit of cc (or shells) is missing the point of using Ca carbonate <as opposed to baking soda>. CaCO3 dissolves in water only under acidic pH. So you dump in a LOT of it, but only a little dissolve, just enough to bring pH up to equlibrium (which is mid 7's). Once pH is up, no more dissolves, so you can't overdose like bicarbonates. As the buffer is used up, the pH drops, more CaCO3 dissolves in, brings up the pH, etc. So basically you have a self-adjusting pH system, keeping the pH rock solid without any work! <Although you don't have a choice what your final pH is - this is determined by what else is in your water, not your dose of CaCO3!>

My suggestion, therefore, is to keep hammering! Put in a few cups of the crushed shells, and repeat every few months as needed.