Tropical Fish Keeping - Aquarium fish care and resources

Tropical Fish Keeping - Aquarium fish care and resources (
-   Water Chemistry (
-   -   How to lower dKH? (

au01st 10-28-2008 07:49 PM

How to lower dKH?
Got the tank all setup and most of the numbers look great. It's currently cycling with some live rock. My dKH is high, 16, so how would I go about getting it down? I plan to keep a number of soft corals, zoas, mushrooms, etc, and don't want them to have any trouble.

My other numbers are:

Ammonia: .25ppm
Nitrite: 0ppm
Nitrate: 0ppm
PH: 8.4 (my tap water has high PH)
Phosphate: 0
Calcium: 420
S.G. 1.022

I don't have a Mg test kit yet, but soon. All the rest of the tests are from A.P.I.

I have not used any additives or buffers. I used Instant Ocean "Reef Crystals" salt mix. Will it go down on its own with time? I want everything to be right before I start adding live stuff. Should I bump the S.G. up a bit more to 1.023-24?

Kellsindell 10-28-2008 07:58 PM

check this site - Chemical Solutions then hit [ctrl] + [F] and type lower alkalinity and what are you trying to keep in the tank? fish soft corals SPS? if coral then you'll need to raise your SG to1.025-1.026

au01st 10-28-2008 08:38 PM

I'd like to keep mostly soft corals, but some sps up at the top of the rockwork may be in the future.

Guess I'll worry about getting that s.g. up before I worry about dKH.

Kellsindell 10-28-2008 08:45 PM


au01st 11-06-2008 01:47 PM

Ok, I've maintained the S.G. at a steady 1.025 for a few days now. My dKH is still high at 16, calcium is 400. All the test kits are under 4 months old from the date of manufacture.

Any ideas?

onefish2fish 11-06-2008 09:54 PM

i personally would just leave it as you said your just cycling at the moment.

its going to drop over time

Kellsindell 11-07-2008 04:23 PM

I agree with onefish, and GJ on rasing your SG.

au01st 11-08-2008 10:13 PM

I've already raised the SG to 1.025 and it's held steady for several days now.

Pasfur 11-09-2008 07:42 AM

The SG will not fluctuate on a regular basis. Some salt will be lost to salt creep, but this adjustment should be minimal. You will also see SG raise due to evaporation, but daily water replacement will prevent this from being an issue. I think 1.025 is on the high end, and would personally suggest 1.023 to 1.024.

Don't be concerned about the 16dkh reading. It should naturally fall. Honestly, given the calcium reading of >400ppm... i am willing to bet that your DKH test result is incorrect.

au01st 11-23-2008 03:44 PM

Ran all tests again last night.

PH - 8.3
Ammonia - 0
Nitrite - 0
Nitrate - 0
Phosphate - 0
Calcium - 420
dKH - 12! :-D
Mg - 1250
S.G. - 1.024-1.025

Everything looks good! I got a Skunk Cleaner Shrimp a few days ago and he is a sight to see. My tank is in the dining area, probably 15-20ft from where I sit on my couch, and I can pick him out from across the room.

All times are GMT -5. The time now is 07:56 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

For the best viewing experience please update your browser to Google Chrome