[DeDeuce]

Hi all,

I'm just getting back into to the hobby after a 4 year hiatus (my wife and I have been raising a new batch of human fry :icon_wink). My wife wanted me to setup a small tank as our 2 little girls are fascinated with fish. Unable to stomach blue gravel and the token bubbling treasure chest, I decided on a planted tank.

My tank... Uh, I mean my girls tank has been up and running for about 2 weeks. I have most of the water parameters in check other than the gH. Out of the tap, the kH is 3 and the gH is 7 but the gH in the tank is off the scale. I do have some indigenous rocks in the tank but I don't believe they are the problem. I added some of the rock chips to some tap water, modified the pH to match the tank's and tested the gH of the sample. There was no difference in the sample and the tap's hardness. I can't think of anything else that might be raising the gH. Anyone have some ideas? Here are some of the tank parameters:

10 gal
3.6 watts/gal
100% Flourite substrate
Heavily planted
pressurized CO2
pH 6.8
kH 3
gH > 20
no fish yet .. only nerite snails

Any help would be appreciated..

--
Don

 

[KDahlin]

Welcome back!

If you happen to have any muriatic acid around, that would be the best way to rule out the rocks. Put a little muriatic acid on the rock, if it fizzes or spits, that's your culprit.

 

[DeDeuce]

Thanks for the quick reply! After thinking about it, like you I'm becoming more suspicious of the rocks. I don't have any muriatic acid but I did put a few drops of vinegar on the rocks and didn't get any reaction per se. I think I will try removing the rocks and do a water change then retest after a day or so.

Thanks again,

--
Don

 

[Rex Grigg]

To really test rock you need to scratch it deeply or break off a chip so you have a fresh face. And you need a more powerful acid than vinegar. You can get muriatic acid at most any hardware store.

But what I find strange is that the KH is not changing at all.

 

[mistergreen]

You can do my unscientific thing where you smell the wet rock. If it smells strong in chalkiness/minerals then it's the rock.

 

[DeDeuce]

Update...

I think I've found my culprit and it turns out that it wasn't my rocks. I retested my rocks with some leftover sulfuric acid from a 4-wheeler battery. Same result, no reaction. The only other thing left was the nerite snails. I have approx 20 snails in a 10 gallon tank. I used so many to help control algae while the tank was cycling (did a fantastic job BTW).

It turns out that snail shells are made of calcium carbonate. Many of the snails I received had noticeable eroded areas on their shells. I took an expired snail (yes, I swear he was already dead) and put some of the sulfuric acid on the shell. Sure enough there was a reaction, particularly on the eroded spot.

My SAE's and Shrimp are on the way now that the tank has fully cycled. Looks like I'm going to thin out the snail population and retest the water. I think I'll see a noticeable difference.

Anybody need some snails? Free to a good home, you just pay the shipping

 

[KDahlin]

20 Nerite snails in a 10 gallon tank did that to your gH? How big are they?

With calcium carbonate, your kH should have been high as well. Maybe your test kit's bad.

 

[DeDeuce]

They range in size... Many are larger than a dime. I tested and retested my tap water. kH and gH are consistent. My kH test may be bad, but after performing the test a few times on my tank water, I did see a slight elevation in kH; about 1 degree. I like you feel like it should be higher. The puzzling thing is that my CO2 test seems to confirm that the kH readings are correct.

--
Don

 

[rain-]

I don't think it's really possible for the snail shells to affect your water parameters that drastically. I would search for another reason. Snail shells are indeed calcium, but the outer layer is organic and is protecting the inner calcium layers (the white ones), so the only place where there would be some calcium going to the water would be the eroded areas and even then the water should be way more acid than it is now to strongly erode the calcium carbonate of the shells (and it would raise both GH and KH a lot and not just GH a lot and KH just mildly). You would need way, way more snails to affect water parameters that much.

If you still don't trust the snails, set up another container for them for a while and move them there, do a large water change to the actual tank and check if the GH is climbing up again. If it is, find the real reason. If it's not, there might have been something you have added to the tank some time around the beginning and it added to the GH. (Assuming that you haven't done much water changes before now.)

What's your fertilization regime, what are you adding to the tank? Water conditioners, other additives?

 

[DeDeuce]

Right now, I'm just adding micro's (Kent Freshwater Plant), macros are on the way.

I've done a few water changes since the tanks inception and honestly, the gH seems to hover around 15-16(much better than it was). The rocks have been out since I originally started this thread.

I'll take your advice and set up another container for the snails, do a big water change, and wait to see if the gH rises. I'm going to also set up another container for the rocks, match my tanks pH, and let it sit for an extended period the test.

The only other thing in the tank is corkboard, flourite and plants.

I'll give an update in a few days!

 

[rain-]

Maybe you could test the Flourite too. Scoop some out (or take some of the unused stuff you might have) and put it in a container with tap water. Let it sit for a day or so and test the water. It shouldn't affect GH, but there isn't anything in the tank that should affect GH, so maybe it's best to test everything.

 

[KDahlin]

Maybe you could test the Flourite too. Scoop some out (or take some of the unused stuff you might have) and put it in a container with tap water. Let it sit for a day or so and test the water. It shouldn't affect GH, but there isn't anything in the tank that should affect GH, so maybe it's best to test everything.

Yeah, maybe Seachem had a contaminant in that batch of Flourite. Not likely, but I know Caribsea's Eco-Complete had issues with phosphate contamination.

 

[rain-]

Yeah, something like that could be possible, even though not that likely, as you said. I did a search before I suggested testing Flourite, I used words flourite and hardness and I found at least three similar (rather recent) threads about Flourite tanks with rising hardness and nothing to explain it. Even though Seachem is a really good company, with people and machinery there's always a small chance of error/malfunction/contamination. But same goes with everything else. Test kits can go haywire with some stuff and things like that, so it's important to check every possibility.

 

[Glouglou]

Bad Snail, bad...

I have the same doubt that the snails can release enough material to change the chemistry in a big way...
If they do, they will probably go naked soon...
:icon_smil