What does my KH mean?

[fish_4_all]

I know it is good for keeping a pH balance in my tank. But where does it come from? My tap water, pH 7.2, KH <1. I know I have some snail shells that are dissolving but where could a KH of 10 come from? I only add the normal Gregs dosing, 10-15ppm KNO3, 1.5ppm KH2PO4, 1/8tsp K2SO4, every other day and .2ppm iron from CSM+B on the other days with a little, 1 tsp of MgSO4 in 100ml water with the CSM+B.
GH 8-9dGH
KH 10 dKH
pH 6.6.

Where is my KH coming from? Is there that much calcium from the dissolving shells? Is there other factors in play here? I really need to know because if I am not purposely making it that high, what happens when whatever it is suddenly doesn't exist in the tank anymore?

 

[Purrbox]

Do you have any Rocks in your tank? Coral decorations? How many and how large are the Shells?

 

[fish_4_all]

No coral, driftwood from the beach, boiled 20 times+ to get it to sink but one tank didn't have it for a while. The shells were from baby ramshorn and the last one was eaten by the loaches that were in there 3+ months ago. I can not see the shells anymore. There are MTS in there right now and they are alive. I do have passive CO2 going into my AC HOB. 100 bubbles/minute or so. Too hard to count as they come out in groups.

The driftwood unknown species, ceramic ornaments but they have been taken out and put back in and the KH stays the same. Out for weeks and in for weeks.

 

[Lonewolfblue]

What is the kh of your tap water?

 

[fish_4_all]

Tap water KH<1. Water does not turn blue with 1 drop.

 

[Purrbox]

Driftwood would lower pH not raise it. The rock is something I would be suspicious of. Instead of just removing it, remove it an place it in a bucket of water. Test the water beforehand to get the baseline KH. Leave it in the bucket for at least a couple weeks and test periodically to see if there is any change in the KH.

Also, have you tested the KH of your tap water recently? If that was an old test result from awhile back, it's possible that the water company has shifted how they're treating the water and it now has a higher KH. Apparently a lot of water treatment companies shift their water treatment in the fall and spring which of course makes things intresting for us. Something that is related, do you have a water softener in the house? If so, could it have run out of salt?

 

[fish_4_all]

The rock is out, has been for 2 weeks and no change. No water softener. Tested it 10 minutes before I posted this today. pH is a lot lower than tap, tap is 7.2 and tank is 6.6. Could this be part of the correlation of pH to KH? I will test the rock to see if it does anything just because. Could plastic canvas cause any of this?

Fish are fine, plants are fine. I have never had such success growing plants. I am just concerned that once the KH cause is gone, will my plants suffer and worse of all, will my fish succumb to a massive pH swing?

 

[Purrbox]

Something else to test is your substrate. Some gravels and specialty substrates will buffer your water.

It's expected that your tank pH would be lower since you're injecting CO2. With a KH of 10 and a pH of 6.6, you've got a CO2 level of 75ppm. Might want to consider cutting back on the CO2 some, especially if you're seeing any signs of stress in your fish. This is assuming that you don't have any other buffers present that would make the KH/pH relationship invalid.

Plastic canvas won't have any affect on your water chemistry.

 

[Lonewolfblue]

I can't remember, but does MgSO4 increase kh or gh? Just a thought of the added MgSO4.

 

[Purrbox]

Yeah I thought of that too... looks like MgSO4 only affects the GH.

 

[fish_4_all]

I will test the substrate also to see if that is a possibility. I know 75ppm CO2, I don't think it is possible but my plants might say differently. Very fast growth from anacharis, wisteria and java fern. Water sprite, cork screw vals and crypts, medium growth. So maybe but I really doubt it. I run an airtsone sometimes all day with no change in pH or KH so maybe. I can't regulate my CO2 unless you know a way I haven't seen yet.

 

[Lonewolfblue]

Actually, it is possible. Especially if you have a good diffuser. And sounds like whatever you are doing is working great.

 

[Purrbox]

I take it that you've got a DIY setup instead of pressurized? If that's the case you can tinker with it by playing with the number/size of generator bottles as well as the mix you use in the bottles. If both your plants and fish look happy you're probably fine, but I'd keep an eye on it.

Eco Complete is known to cause a temporary spike in KH. Onyx Sand states right on the packaging that it buffers your water. If you happened to use a substrate intended for SW, those often buffer the water as well. Some gravels do too, but you have to test to be sure on those.

 

[malkore]

I've never seen more than 3-4dkh increas from Eco.

you have next to zero buffering in your water, so the CO2 is going to majorly affect pH. Why are you injecting Co2 with a Kh less than 3?

the acidic environment could be dissolving the snail shells and increasing Kh that way.

I'd also have a second test kit used on your tank. I was under the general assumption that water in the WA area was fairly hard....not soft.

 

[fish_4_all]

My tap is KH 0, my tank is KH 10, it is coming from the snail shells. I have that. How do I prepare for the time when and if the shells stop raising my KH and I have to add something. I don't have Eco. Just gravel. I have called the city for information. I will calibrate my KH test as soon as I have time.

The only thing I can think of is to add crushed coral in very small quantities so that my KH increasing factors don't vanish and I don't catch it before my fish suffer.

 

[fish_4_all]

Ok, KH and GH tests come up to be within 1 drop or there abouts. I made a solution for GH, solution was made to 10 drops and tested out at almost 11. With my teaspoon measuring I figured that was fairly accurate. When I test my tap water for KH, I don't get blue with one drop but I don't get bright yellow either. Maybe there is a reading of 1-3 but I can't confirm that yet from the city.
My gravel, in plain tap water overnight has not changed the KH or GH. I washed it really well so I don't know if that was the right thing to do.
I also put a ceramic piece, unglazed in a cup of water and have not noticed a change yet although the test did maybe show a little more blue than tap water so I will keep that test going along with the gravel to make sure. The rock hasn't changed anything yet either. How long should I test them to make sure they aren't the cause?

If a KH test doesn't turn blue when shaken but you do see a tinge of blue when you drop it in, what dose that mean? The test goes bright yellow after 4 drops. Tanks water turns bright blue with 1 drop and yellow after 9-11. I am doing it right and recording the color change as soon as it goes from blue to yellow and not neccessarily a bright yellow, correct?

Edit:
Sorry, KH was verified with LFS, they tested at 11, mine tests at 10. Has been a really bad month and a really bad day, trazodone is not fun, especially the first dose, or so it seems.

Also, can Aquasafe change your KH or GH?