How Big a Piece of Limestone?

[Rhaethe]

So.

Further reading about my 2 nerite snails tells me that my water will eventually damage their shells. For that matter, my water is pretty horrible for most inverts. No hardness whatsoever (readings of 1 at best on both tests). Ph stays around 5.5 - 6. After a water change, it can pop up to 6.5

Any fish I've ever had in the tank seem to have no issue with it (other than the 3 cardinals I tried months and months ago). I have very little luck with inverts. And while my anubias is sending out cute little rootlets, my amazon swords are doing the melting thing.

So.

Rather than do additives from a bottle or constantly add baking soda whilst doing water changes, or any of that sort of thing ... I figured I should simply find a nice piece of limestone I can add to the tank. Adds buffer, calcium for inverts, and decoration, too. I'll be removing the amazon swords this week and replanting, so might as well take the opportunity to "redecorate" a bit, as well.

For a tank that holds around 6g, about how large a piece of limestone should I acquire? And is there any specific method by which I need to add it to the tank?

[Northernguy]

I would stick it in a bucket of water after the water has aged 24hrs in the bucket.Test the water before you add it and test again in 24hrs after its added.
It should give you a good idea of how high it will adjust your ph.
I would start with a 1lb stone.
Tafu stone works well too.

[Rhaethe]

Tafu stone?

What does it look like?

**goes off to google**

[Cascade]

When I was looking for limestone, I wanted something different than holey rock (and cheaper!). I went to a landscaping company and bought some large limestone rocks...like the kind meant for building a wall or something. Then I had my husband take a sledge hammer to them to make smaller chunks for me. I used these pieces to build a big mountain/cave structure in my cichlid tank - obviously way bigger than what you're going for, but you could do the same thing on a smaller scale. The smaller pieces will offer you more surface area for the minerals to dissolve into the water (similar concept to why small ice chips melt faster than a huge cube), and you have some flexibility as to how you want it arranged. I agree with NG, too, to do some test runs to see what it will do to your pH. I wanted to go really high with my pH and hardness, and it worked quite well for me (but I also add a homemade salt/buffer mix at water changes, too).

[jcclark]

I've seen people put crushed coral (used for saltwater tanks) in a sock like
the end of a pair of pantyhose and hide that in the aquarium.
It's suppose to raise it pretty easily.