Explain Alkalinity, Hardness, and pH relationship to a newbie

[biomanz]

The way I understand, alkalinity is buffer that helps water resist changes to pH, keeping it slightly higher (?) and commercially products should be used to increase it - can anyone recommend a product?

Hardness is mostly calcium and magnesium along with other soluble minerals in the water.

So to raise the pH, can I raise the buffer, and will that increase hardness? Inversely, does hardness have no impact on pH or alkalinity?

And can I let cuttlebone dissolve to increase calcium and hardness, and crushed coral for alkalinity? Or am I missing other essential minerals/ions a commercial product offers?

My tank is for crayfish and a few tetras.

Thanks!

 

[kangster]

i had a crayfish with a small clown pleco and some feeder comet goldfish
the crayfish ended up snacking everyone...even the pleco...yes the pleco
he couldnt finish eating the pleco because the shell was too hard for him probably...
how big are the tetras and the crayfish?

 

[biomanz]

The red eye balloon tetras are just under an inch and the crays are 2-2.5 in. First day and the crays are just cautious of them it seems. People keep fish with crays with varying success so I'm testing my luck with these 4 tetras.

 

[HN1]

You shouldn't really need to dose for alk if you're just concerned about available calc for your crays. I would just drop a cuttlebone in and let it float for a couple days until it sinks. Then hide it where ever you want. Likewise with Mag. Shouldn't need it unless you're running a reef system.

More than I ever wanted to know...
pH - Wikipedia, the free encyclopedia

 

[msjinkzd]

What does your source water test at for ph, kh, and gh?

 

[biomanz]

My tap water reads:
pH - 6.4 (bit low for crays)
Alkalinity - 80 ppm
Hardness - 25-50 ppm

I just got some Seachem Alkaline buffer. I'll be trying it out soon.

 

[jsoong]

Well, you are ALMOST right in your understanding of pH, etc.

Alkalinity is the amount of buffer in your tank. Buffers resists pH changes & help keep it stable.

There are many kinds of buffers, each will drive the pH towards a specific pH value. It is possible to get buffers that will drive the pH lower as well as higher. The higher the level of a specific buffer, the closer the water will be to its equilibrium pH. It will not go past the equilibrium point, no matter how much you add. If you have 2 or more buffers, the pH can get extremely unstable ... swings between 2 equilibrium pH's, it all depends on what the buffers are as to how the pH will behaves.

Hardness (GH) is the concentration of Ca & Mg in the water. Crays & most inverts need a certain amount of hardness as Ca is the main component of their shells.

The safest way to increase both hardness, pH & KH/alkalinity in a *carbonate* buffered water is adding a carbonate source ... Ca CO3 - crushed coral/crushed shells or limestones. <Most water sources are carbonated buffered, but there are exceptions.>

Seachem alkaline buffer is basically carbonates. It should work the same as crushed coral, but is much more expensive .... There are "secret ingredients" that Seachem claims are necessary, but I would disagree .... Since you are not adding it to distilled water, the other ions are there in your source water, so adding more is not necessary.

If you have "strange" water, or if you want to buffer at low pH, then the safest way to do that would be to start with R/O water & add the appropriate buffer for the desired pH.

 

[biomanz]

Alrighty, so alkalinity and hardness can both vary depending on the types of minerals/ions in the water. I just added Eco Complete substrate, and it says I shouldn't add crushed coral, limestone, shells, and a few other things so I think I'm stuck with aftermarket stuff.

 

[msjinkzd]

I would just put the crushed coral in a media bag in your filter. I really think that using something like crushed coral over the seachem is a better idea. As far as buffering for invertebrates, you could also make plaster of paris pucks to buffer the water. Here is a recipe you can use to make your own if you are interested, these are great for snails as well:

Ingredients:

1600 mL of plaster of paris (Dap brand from Home Depot)
800 mL of water
1 100g container of tetra color sinking goldfish granules

Tools needed:

A large plastic pitcher
A 1L measuring cup
3 ice cube trays
A stir stick

Mix the water with the plaster until completely smooth.
Add fish food and mix evenly.
Pour into the ice cube trays. Rattle to trays to remove air bubbles. Let sit in a dry place for 2 days. Once the trays are good and solid, twist to remove the blocks. If the blocks are crumbling or breaking, they are not dry enough yet. Once they are out, cure them in a dry place for five more days (or use a food dehydrator). Once cured, they can be vacuum packed for storage. Each feeder typically lasts two weeks.

*The calcium in these feeders will buffer water to help maintain a basic pH.

 

[jsoong]

I am not sure why EcoComplete has a problem with CC ... prob something to do with the Iron in the ferts ..... but you might want to ask the plant gurus at the planted forum.

However, I think the injunction is for not mixing the cc in with the Eco. It should be fine to have carbonates in the water. <After all, people with hard water already has the CaCO3 in the water.> Plus, adding the Seachem buffer is the same as adding carbonates, because the main ingredient is CaHCO3. So I think you should be fine adding a bit of cc in the filter.