GH Off the Scale...

[Alshain]

Ok, so either I'm doing the test wrong or it took 18 drops with the AP GH Test to change colors. In the tank I have Eco-Complete, Plants, 2 big pieces of Malaysian wood and several stones which were identified as quartzite, and ammonia. Any ideas what went wrong? The last time I did it, it was at 11 degrees. (FYI I had no problems with the KH test and it did just fine at 7 degrees)

 

[dskidmore]

What does your tap water test out at? Around here we have seasonal changes in the tap water.

Are you shaking the tube between drops?

Might take the stones out and put them in small container, and see if the GH raises over time in the container. Many rocks have impurities beoynd the base mineral, so just because it's quartzite doesn't mean the whole rock is inert.

 

[Alshain]

Yeah, this is true, but 2 days ago I tested at 11 degrees and now I'm at 18 without altering KH. I thought it was difficult to alter GH without altering KH. Most stones such as limestone and marble would alter both. I have some leftovers I can do that test with, but the more I think about it, I think I must have screwed up the test. I'm gonna try again when I get home.

I certainly hope I screwed it up. I went to a lot of work building the caves and terraces from this rock, I'd hate to have to remove them.

 

[dskidmore]

KH raises GH, but GH doesn't always raise KH. There are other disolved minerals that increase GH. Most commercial buffers work on KH, and therefore both, but there are plenty of others not sold on shelves.

 

[Alshain]

Tested again,

Tank is 19° and tap water is 7°

I looks like its the rocks, but before I throw out all my hard work, Is there any chance that the ACE Hardware ammonia or the Pottasium Sulfate or Plantex CSM+B or Pottasium Nitrate could be causing these readings?

 

[dskidmore]

I don't think so. I'd blame the rocks.

If you're worried about something planted on the rocks, you could always upgrade the lighting on your QT.

 

[Alshain]

Its not planted on the rocks, its the 6 days it took me to glue together the rocks in the fashion I wanted them in not to mention that if I throw these out, they will not be getting replaced as aparently there are no rocks in Texas, at least not usable ones. As for the QT tank... I'm not sure what you meant, this is my new display tank

 

[Thebluyak]

lol I can ship you a some rocks but it would be $$

 

[dskidmore]

You could always take the rocks out as a temporary measure and see if it helps. If they're not the culprit, you can always put them back in.

 

[Alshain]

Yeah I probably will take them out, actually I will probably wait till after the fishless cycle so I can doa water change. If it is the rocks, I might attempt some method of lowering GH. Maybe peat moss in the filter, I'd like to avoid a sodium softener if possible.

 

[dskidmore]

Driftwood!

 

[Alshain]

Driftwood!

I have two large pieces to the right of the cave and the left of the terraces. It doesn't seem to be helping, maybe I boiled it too much.

 

[dskidmore]

You'll know the driftwood is working when the water starts to turn a little yellow when it's time for a water change. Otherwise you might not have enough.

Peat in the filter is pretty easy to add.

 

[Alshain]

I never updated this, but I think the GH was something that didn't get washed off the rocks (they were all covered in dust and crap). After a few water changes the GH stopped rising.

 

[happygirl65]

That is great to hear! I have been watching this thread as I am attempting a similar rock scape for my tank. I know the work involved in glueing them together just right. I would just like to add that from your pics you did a great job.

Glad to hear your GH stopped rising.

Best wishes!

 

[fish_4_all]

Ok, I may be worng, won't be the first time but if GH is 7 at the tap, then couldn't it go up to as high as 14dGH with 50% weekly water changes?

I know it works that way with other nutrient dosing like NO3 and PO4 so doesn't it work that way with GH because it is just ppm of magnesium and Calcium?

 

[dskidmore]

Um, with weekly water changes alone, the hardness should not get significantly higher than the tap level. (Little bit of evaporation, that's it.)

If you have rocks or something adding a soluble mineral to the water, the total amount in the water will not get above 2x the total amount leached per week with weekly 50% pure water changes. The amount leached is generally unknown, but decreases over time.

So I guess the maximum hardness with weekly 50% tap water changes would be your tap water value, plus 2 times the amount added per week by leaching materials?

 

[7Enigma]

Ok, I may be worng, won't be the first time but if GH is 7 at the tap, then couldn't it go up to as high as 14dGH with 50% weekly water changes?

I know it works that way with other nutrient dosing like NO3 and PO4 so doesn't it work that way with GH because it is just ppm of magnesium and Calcium?

I don't understand your question? If your dosing nitrAte and phosphate, your generally doing it because it is getting used up by your plants. At the end of the week you probably have LESS than you started the week with, otherwise there would be no reason to add them in the first place. If the GH is 7 at the tap, it can go to any level or not move at all depending on how much rock is breaking down during that time. If the rock is relatively inert, that 7 value should go down slightly as the plants are using the calcium and magnesium.

If, OTOH, the rock continues to dissolve in the water you would have increased GH levels. And unlike fish which generally will produce a set amount of ammonia if feedings are kept constant, rocks that dissolve can drastically change their rate as seen in this example. There may be impure pockets with higher or lower amounts of Ca/Mg, and this can change the rate at which it increases your GH levels. That's why I personally don't want anything in the tank to affect my levels, I like the ability to change them or not change them at will.