Mega High KH

mdcorcoran · 03-20-2004, 05:54 PM

I had my water tested today. Everything in my tank is doing very well, except for the doughnut coral. Ca was 431, sg was 1.024, pH was 8.2, but my KH was so high that it was out of the range of test kit. I use well water, and we are on a limestone base here, so that is obviously why my water is so hard. So I'm starting to use RO/DI water (RO/DI/UV filtered at Wal-Mart for 33 cents a gallon) and switching from Coralife salt to Instant Ocean. I am thinking about changing 10% a week in my 37 gallon to bring down the KH. Anyone have any other suggestions to help bring it down?

mc

gregt · 03-20-2004, 05:58 PM

I think there was probably an error in one of your tests. What kind of kit are you using.

If your Ca is 431 and dKH is actually off the charts then the Ca should be precipitating covering everything in site with a white Ca coating. I don't think it's physically possible to have those readings at a pH of 8.2 and not have a completely white tank.

hankstanks · 03-20-2004, 09:06 PM

Ditto,,, if your CA is that high and your PH is in check your test was off.

I would test it with another kit. I would test both the fresh water and the mixed water just for a comparison.

tdwyatt · 03-20-2004, 09:07 PM

ditto,supersaturation quotient of "off MY charts" (at 15 dKh or higher) would be around 7 or higher (supersaturation max is around 6 for a balanced Ca /alk and pH of 8.2 at aquaria temps of 80F without precipitation). At aquaria pH, be suspect of your test kit or methodology.

How do you supplement Ca and alk, which kits are you using to test alk and Ca, and how do you measure your pH?

mdcorcoran · 03-21-2004, 12:14 AM

I had my stuff measured today by a guy a met who runs a maintenence & shop out of his garage. I made an appointment to check it out, because I wanted to get a test kit, especially for Ca and KH because I know our water is so hard here. He was out of test kits, so he tested it for me, I'm pretty sure the kits he used was a salifert. First thing he checked was sg, with a refractometer, and it was 1.024. then he did the KH test, and said KH was so high that it didn't cause a reaction with the reagent. I think it is a color changing reaction, no? He then checked Ca and pH, which were fine, but didn't check anything else because he said with the KH being so high, it would be skew test results for Mg or I2, etc... I think i'm better off using the dDI/RO/UV water anyways, and I'm going back to the shop next weekend to pickup my own test kit, then I will be able to compare the water from a few different faucets here, some that are supposed to be hard and others that go through the water softner, then I will compare some makeup water from each group, made with Instant Ocean and some with Coralife, just for my own enjoyment and experience.

Here is another question: Is a 5 gallon water change, twice a week (37g tank) too much?

tdwyatt · 03-21-2004, 02:51 AM

Quote:

Originally posted by mdcorcoran
... then he did the KH test, and said KH was so high that it didn't cause a reaction with the reagent. I think it is a color changing reaction, no? He then checked Ca and pH, which were fine, but didn't check anything else because he said with the KH being so high, it would be skew test results for Mg or I2, etc...

If you mean the color changes to match a color chart, I would not put too much into the results, but if you mean a titration kit that changes color at the endpoint, then so long as the reagents were in date and properly stored, they should be OK. You'll be better off making your own water and mixing your own ASW

Quote:

Originally posted by mdcorcoran
...Is a 5 gallon water change, twice a week (37g tank) too much?

I don't think there is anything wrong with this, but it is a bit wasteful unless you have a heavily fed tank with many high-protein-consuming fish living with corals, even then it might be unnecessary. If your tank is 37 gal US, then you will have a thriving system of corals with a 10% change once a week. Turn off any autotopoff devices, use a siphon and a calibrated bucket to siphon the rock until you remove your water change, then blast the rock and turn the skimmer up to clean any remaining detritus in the rock. 10% will be about 3 and 3/4 gal (around 15 liters). If you do use a wet skimmate for a few hours, don't forget to make enough extra ASW to replace the SW the wet skimming removes, and don't forget to adjust the skimmer back down. Once you've replaced all your seawater, turn the auto-topoff back on as well.

Yu should be set for another week.

mdcorcoran · 03-21-2004, 11:24 AM

The KH was a titration test, not a color chart.