using coral

[falco]

hi.can anyone tell me if using coral gravel is ok in a new tropical freshwater tank?or will the ph climb too high?

thanks for the welcome

garry

[Fishguy2727]

What kind of fish?

What does your water hold at to begin with?

[falco]

havent decided on fish yet.its a fluval 190l tank

[Lady Hobbs]

Same question has bugged me for 2 years. I was given a large piece of califlower coral by my daughter as a gift ($55). It was where shells are sold so had been cleaned and processed. I boiled it myself again to make sure no lingering things were inside it and also to see if any salt should boil away. Nothing. Salt will scale when boiled in a pan and none of that was present.

However, I've been told to use even dead coral in a freshwater tank can be toxic but no one will tell me why!!! Any meaningful explanation would help and even the Tom and Bob Nevine put this question on their radio show when I wrote them about it. Meanwhile, this coral is packed away never to be used, I guess.

You just inspired me!

OK.........I just plunked it in my 10 gallon that has my lovely danio's. LOL May as well give it a test run. I will let it sit in there a few days and test the pH.

I'll tell ya what drives me nuts. You are advised if your pH is low to add a few coral shells to raise it. So how can adding a piece of coral be toxic? HUH?

[Fishguy2727]

They are not toxic. They are used in saltwater tanks and fequently in tanks of African rift lake cichlids. They can mess with the pH, which some may equate to 'toxic'. Then they tell someone it is toxic, then they tell someone, then everyone is thinking it is true.

[Lady Hobbs]

Gawd! Finally a decent answer! My pH is already 7.6 so this may not be wise to even use it as the piece is quite large. I will give it a test run and see how it goes. THANK YOU FOR THE COMMON SENSE ANSWER.

[Incredulous_Ed]

If you are keeping lvebearers and other hard and high ph fish the coral will be okay, but onlty with those typed of fish. Be sure to research what type of fish you plan to keep before you put the crushed coral in.

[falco]

many thanks for your answers

[A340]

Adding crushed coral to a freshwater tank is a fantastic and natural way to raise your pH levels and keep them there. But as other members above have said, decide on what fish you want first, then decide if you need to add the crushed coral.

[Fishguy2727]

I have heard (and the 90 gallon at work supports this) that it will only raise the pH to about 7.6. We have 80 pounds of crushed coral (calcium carbonate, just like shells, coral skelatons, etc.) in the 90 at work. It doesn't ever get below 7.6 and I have to use a bit of baking soda to raise it to the desired 8.2. It has a lot to do with how much calcium carbonate is in there, how much surface area it has, how big the tank is, and what the pH is to begin with. Since acid will dissolve it, it will have more of an affect in a tank that is starting from 6.2 than a tank already at 7.4 for example.

This is why I use buffers when I need to screw with the pH.

[Lady Hobbs]

Then possibly wood in the tank will off set whatever rise in pH it does give.

[Lady Hobbs]

Fishguy......I checked the pH after 24 hours and it remains at 7.6 using the low range pH test. I then tried the high range pH and get a reading of 7.8 which is the same as I get from my other tanks.

It may have raised it slightly but I can't tell, really. Trying to match the color chart does not give an exact pH but I can see no difference in what it was 24 hours ago. And it's in a 10 gallon tank.

I can actually see more of a difference in pH from tank to tank according to which has an airstone going than from that piece of coral.

[Fishguy2727]

Sounds right. Crushed coral usually only brings it up to 7.6. I would say if you like the look of it, put it in a tank and enjoy.

[Lady Hobbs]

Thanks again for all your help. Really been wanting to use this piece.