kH problems

[Bill Nye]

I have been having kH problems in my tank recently. For the past couple weeks my kH has been between 7 and 7.5. When I test a fresh batch of water im going to do WC with it tests out to 9 - 9.5. How can the kH in my tank be so low when every week I do a ~20 percent change with water that has a 9.0 kH?

 

As far as stocking goes I have some zoa/palys, a chalice and 2 ricordea. My tank is very lightly stocked..not sure what is going on. I also tested the calc level in my tank and it was at 420.

 

Thanks for any insight.

[lakshwadeep]

It could be that the WC water has not be aerated enough to show the actual long-term alkalinity (likely from elevated indoor carbon dioxide levels). What's your pH level? 7 dKH really isn't bad; it's a the low end of the normal range. Also, if the corals are fine (the chalice is the only one with a hard skeleton), you don't have a problem. This is a good guide to the normal ranges of all major water parameters:

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

[Bill Nye]

It could be that the WC water has not be aerated enough to show the actual long-term alkalinity (likely from elevated indoor carbon dioxide levels). What's your pH level? 7 dKH really isn't bad; it's a the low end of the normal range. Also, if the corals are fine (the chalice is the only one with a hard skeleton), you don't have a problem. This is a good guide to the normal ranges of all major water parameters:

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

 

 

Thanks for the reply. When I test my water it has aerated for at least an hour but you may be correct. I have switched salts to ESV about a month or two ago, which is supposed to mix to about a kH of ~9. I was using just regular IO and my alk was always around 10 to 11. There is a window that is near my tank that I always leave open. I am going to try mixing a cup of my tank water outside and see if that changes the story.

[SherifBart]

i aereate my water for 24 hours. that is the prescribed method. can you get away with less? yes, as i have had to do in emergencies. other than that my guess is your ph and/or mag levels are low. check those out and bring those in line. ph 7.9-8.3, mag 1250-1400

[Bill Nye]

i aereate my water for 24 hours. that is the prescribed method. can you get away with less? yes, as i have had to do in emergencies. other than that my guess is your ph and/or mag levels are low. check those out and bring those in line. ph 7.9-8.3, mag 1250-1400

 

 

My mag is around 1400. My salt mixes to about 1460. Last time I checked my ph I was at 8.2. I am gonna run the full gamut of tests again tomorrow and well see what the problem is.

 

edit

 

Also the only time I only aerate for an hour is when I make a new batch. I typically make 4 gallons at a time. So that takes me about 4 weeks to get rid of. I leave it covered with a powerhead and heater.

[Nano sapiens]

Possibly low Mg, even with a 20% WC. Do you test and add Mg supplements?

[Bill Nye]

Possibly low Mg, even with a 20% WC. Do you test and add Mg supplements?

 

Yes although I havent tested in a while. I tested the first 2 batches of water I made with the new ESV salt. They both came to about 1460. My mag was about 1200 before switching salts due to crappy IO. I usually write down all my parameters with the date but for some reason I dont have my last mag test. I believe it was around 1350 though.