PH and Crushed Coral

Nov 5, 2002
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#1
I recently read/herrd that adding a small amount of crushed coral to your freshwater tank will help raise the PH level naturally and without the need for potentially harmfull chemicals.

Has anyone out there heard the same thing? If this is true how much should you add to a 29 gallon tank with extremely low PH (6.0)?

I am interested in getting the PH up but I am reluctant to add chemicals. Not only can they be harmful but expensive as well and crushed coral is relatively cheap.

Any advice would be appreciated.



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Luca

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Jun 9, 2003
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#3
Seashells do the same thing. Both seashells and crushed coral will raise ph, gh (general hardness) and kh (carbonate hardness).

It is a good idea to have a storage tank of water in which you can add tap water, leave it for 24 hours with some crushed coral/shells in there with a bubbler too (to off-gas CO2 and thus also raise pH), and then add/pump it into your tank. This way there is no swing in pH, gH, kH for your fish. Also have crushed coral/shells in your tank to maintain those conditions.

Goodluck
 

TaffyFish

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Jan 30, 2003
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#4
Would you consider that bicarbonate of soda (aka baking soda or sodium bicarbonate) is one of those

potentially harmfull chemicals
?

Bear in mind that there are many (hundreds, thousands?) of us who keep African rift lake cichlids adding this and Epsom salt (magnesium sulphate) to our tap water.

Pre-mixing with such chemicals gives the increase in KH, GH and pH that we need and, more importantly, we can also ensure stability of that pH, usually around 8.2-8.4

Why is adding crushed coral more "natural" - what chemicals is the coral releasing to increase the hardness do you think? Often people use calciferous substrate and rockwork as an added buffer, to defend the tank against fluctuation, not as the primary method of adjusting the pH.

Using a buffering substrate will not give you stability, your pH will be up and down like a yoyo with every water change and take time to stabilise. You should consider stability to be a much more important goal than the optimum pH for breeding.

If you check around, you will also find that bicarb and Epsom salts are a lot cheaper than crushed coral.
 

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Joanne

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Mar 31, 2004
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#5
I have a similar type of question except its lava rock in my tank causing my PH to go up. My normal ph is 6.5 but with the lava rock its currently 7.5. Will it keep going up or will it stabilise at some point?

My plan is that if it stabilises I will use bicarbonate of soda to change the ph of the water I would be adding during water changes to the same ph so there arent fluctuations.

Btw there arent any fish in the tank right now - its fishless cycling.
 

TaffyFish

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#6
It won't keep going up indefinitely, it will stabilise. The rock will only dissolve if the acidity is present, the water will reach a pH value at which it stops dissolving. As the pH rises the water is getting less and less acid so it's ability to dissolve reduces.

Another example is the shells that are in Lake Tanganyika. (That shellies live and breed in.) In acid or neutral waters shells normally disintegrate but because the pH is so high the shells don't degrade at all, so some of them have been there for hundreds and thousands of years. Further calcium deposits on the shells actually makes them stronger and binds them together.
 

Somonas

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Oct 22, 2002
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#7
Taffyfish I am having a hard time with your first post in this thread. are you saying Bicarbonate of Soda is a potentially dangerous chemical? are you saying that by using baking soda and epsom salt you will have a constantly fluctuating PH?

I say B.S. to both statements and would like to see proof otherwise. its quite possible I just misread your post its still quite early in the morning.
 

TaffyFish

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#8
LOL! Take some coffee Somonas and read it again. I am questioning SomethingFishy's view of harmful chemicals. I am suggesting that he is more likely to avoid fluctuations if he uses chemicals than if he relies on a buffering substrate (ie crushed coral) as his primary method of adjusting pH.

How's the morning in Ottawa?
 

Somonas

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Oct 22, 2002
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#14
the only advice I can really give is keep watching the ph. if you do a waterchange test it right after and every 12 hours thereafter... the only person who can truley know what is going on is you because we don't have access to your tank :D and every tank is different.
its quite possible that your rocks etc will raise the ph to x.x and plateau there, and then for some reason go up more in 2 days....
 

Luca

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#16
Joanne, do you run an air bubbler? This off-gasses CO2 out of the tap-water and raises the pH as a result. I'd say a more likely explanation is the rocks, as mentioned: just keep testing.

Taffy: crushed coral lasts longer than does baking soda and epsom salt and therefore may work out more or equally cost effective perhaps? It's also less fiddly to just leave it in the tank as part of the substrate, and if you use a holding tank, as i suggested, there is no fluctuation of the water going into the tank as is going out of the tank.
 

TaffyFish

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#17
I take your points Luca but would stand by my opinion that such a substrate should be used as a precautionary buffer rather than as a primary means of adjusting pH. Certainly the economics of bulk purchase of baking soda and epsom salt (I buy 5kg at a time) versus coral is open to local market fluctuations. Wouldn't the choice of crushed coral as a substrate be made primarily on its buffering capability but on its aesthetic appeal and suitability for the fish? Perhaps the most compelling argument is that of control. Simply by testing the tap water before and after the addition of salts/bicarb the fishkeeper can adjust the parameters consistently, speedily and reliably. The effects of buffering substrate and rocks, I would suggest and many discussions here bear out, are not controlled, reliable or quick. That's for me Luca, if what you do works for you, fantastic.
 

Nov 5, 2002
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#18
WOW I really appreciate all the "talk" generated by my question.

As for the comment on "harmfull chemicals" . . . I was merely stating that it seems that it would be much easier to add a small amount of crushed coral to your tank to stabilize the PH rather than constantly adding chemicals and hoping to get the doseage correct. My thought was (possibly incorrect and therefore why I posted) was that the crushed coral would slowly adjust the PH and then stabilize . . . much like a previous post indicated.

As for the cost of crushed coral . . . yes it is more expensive than gravel or sand but I only puchased 1 pound and that was less than $2 USD. I have added a very small amount (maybe 1/4 cup) inside the filter of my 29 gallon. At 24 hours there has been no change. I will check again tonight (3 days later) and if still no change I will ad more.

I totally agree with the comment about stability being preferred over constant fluctuation while attempting to create a certain PH level. The tap water from my home is high PH (8.0 or so) but I have never seen my tank at a PH over 6.2 . . . even after a 30% water change.

If there are interested partys (as determined by responses) I will try to post the results of the addition of crushed coral to my tank and its effect on the PH.

Thanks again for all of the insight and comments.



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TaffyFish

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#19
So the problem for you, SomethingFishy, is that your pH 8.0 tapwater is reducing to 6.0 in the tank over time, and you're adding the coral to the filter to get the pH back up and then stable? You're struggling to get it higher than 6.2?

Do you know what's causing the reduction from 8.0 to 6.0? It might be a whole lot easier to address that than work out methods to bring it back up again?

What's your target pH? It would save you a lot of effort and cost if it was much closer to the tapwater value of 8.0, right?
 

Nov 5, 2002
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#20
I have no live plants, standard gravel and a couple of pieces of driftwood. It is a 29 gallon with filtration handled by a Penguin 125 BioWheel and an AC Mini. No live plants or rock other than the gravel substrate.

I have been told that the driftwood will cause the PH to drop but I was not prepared for it to make it go down that low. Some have asked before (in previous quesitons on this topic) why worry? Well I have had some fish die and the only explanation I can think of is the PH being so low. My thought was then to attempt to raise the pH to Neutral (or closer to it) using this method.

I am not stressing out over this but rather this is my latest preoccupation with regard to my tank (cant buy more decorations, filters, food or fish so work on the pH)
and I find it perplexing. I have not seen anyone (on this board) with issues of having a PH as low as mine.

Can such a low PH be harmful to fish? Currently I have 13 Tiger Barbs, 5 Checkerboard Barbs, 1 Otto, 1 Clown Loach (3 have died) and an ADF. Water changes every 10 days or so of 25% to 30%.

Comments???


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