KH really high

mikeanddanielle · Feb 13, 2010

I just set up my newest tank and it has been only cycling for 4 days now. I decided to get the cal and alk set so I got the calcium up and then checked the alk with my kh test and it read 20dkh so I retested and got the same reading then I tested the tank I got running now and it was right where it should be so that told me that the test kit wasn't way off like I thought. The ph is reading 8.4 so I'm really confused. Is this maybe cause it's going through it's cycle? I have a few rocks that were the diy aragacrete so I thought that was it but they were cured and as I said the ph isn't real high just the kh/gh. Any help would be greatly apreciated. Thanks

tangdiver · Feb 13, 2010

I would say it is the rock DIY, it has high alk as well as high pH......need to do more curing and flushing with freshwater....

Just my thoughts.

lReef lKeeper · Feb 13, 2010

id have to agree, DIY rock is infamous for it

mikeanddanielle · Feb 13, 2010

That was exactly what I thought but I cured it untill the ph wasn't going any higher then the water was before I put it in also's it's been curing for almost a year since we made it and had to delay our new tank upgrade and also it's only around 40lbs in 200 gallons with live rock on top of it but I think I'll just toss it since it's only a little bit and after the tank has cycled I'll see if it lowered enough and go from there. Thanks

bfessler · Feb 14, 2010

It may be that the agrocrete just needs to be rinsed well before putting it into the tank. You said it had been curing for almost a year. Was it in water that whole time or curing dry? The Agrocrete needs to cure for several months in water before it will leach out all the alkalinity from the concrete, preferable with a power head running to circulate the water and the fresh water should be changed at least weekly. You could try soaking it in some fresh water with some vinegar to cut the alk. Some freinds of mine cure theirs by placing it in a stream for 2 to 3 months.

Underwaterparadise · Feb 16, 2010

What salt brand and what level is your salt @? I have seen freshly mixed water as high as 17 DKH.

mikeanddanielle · Feb 16, 2010

It's instant ocean and i have it at 1.024. kh has dropped from 20 to 14 since I posted a few days ago so I've left the diy rock in and hopefully by the end of the cycle it will drop. Now that you mentioned the salt I have noticed in mi other tank that it does go up with water changes so I think I'll test some freshly mixed salt and see what reading I get out of it.

spongebob · Feb 17, 2010

Did you use RO or tap water?

bfessler · Feb 17, 2010

Alk will generally go up with a water change. This is because it is used up by corals and coraline algae as they create their skeleton structure and encrust. The alkalinity will also be used up by fish waste as these acidic compounds break down alkalinities buffering effect on the water. If the alk has dropped from 20 to 14 I think it was just some residual effects of the curing of the cement and you should be fine. I would probably do a few water changes just to be sure before adding much livestock to the tank.

mikeanddanielle · Feb 19, 2010

spongebob said:
Did you use RO or tap water?

I used tap since we just got our ro filter and we didn't have the patience to wait but we used tap on our other nanos but we did have trouble with algae which is why we bought an ro filter. Does tap usually have high alk?

mikeanddanielle · Feb 19, 2010

bfessler said:
Alk will generally go up with a water change. This is because it is used up by corals and coraline algae as they create their skeleton structure and encrust. The alkalinity will also be used up by fish waste as these acidic compounds break down alkalinities buffering effect on the water. If the alk has dropped from 20 to 14 I think it was just some residual effects of the curing of the cement and you should be fine. I would probably do a few water changes just to be sure before adding much livestock to the tank.

thanks for the reply and thanks to everyone else for the input. I've been into reefs for 10 years but never tested many of my paremeters till I got into sps so I got more learning to do which makes the hobby that much funner...sometimes lol