Jump to content

question about alk


dsoz

Recommended Posts

I just got an Elos Alk test kit on Friday (Thanks Joel), and went home and tested my main tank and it had an Alk of 6 dKH.... Joel told me that it should be 8-14 with 10-12 being best. When I saw 6 I was shocked!!!! So I started adding two part solution. Equal parts of Ca and alk, just like they say to do at the blukreefsupply.com. Then I started thinking... How about testing my Calcium. I have an old API testkit that I got a while back, and it was about 500! If I remember right, it should be about 420-480. How can my calcium be so high, but my alk so low?

 

I know that in the instructions for the Elos kit it says that 1 drop=1dKH, but on the quick card it says 1 drop=0.5dKH. Joel told me that the card was right, and the written instructions were wrong.

 

So Friday night I added more alk (but not calcium) and got the alk up to about 8 over the course of a couple of hours. Then Saturday morning I was curious about my alk again, and tested... Back down to 6 (12 drops)!!! So I added more alk, and over the course of the day raised it up to about 9.5. Guess what it was on Sunday morning? Back to 6.5????? How can my tank be using so much alk, but the calcium stays up? I don't get it.

 

I just tested right now, and my alk is still about 500, and my alk is about 8.5, but that is by adding a large amount of sodium carbonate and sodium bicarbonate to my system after work. I thought that the mix of the two, carbonate and bicarbonate, would help keep the pH stable. I have not seen any adverse affects from this so far.

 

Any suggestions?

 

dsoz

Link to comment
Share on other sites

One thing I have spent alot of reading on is PH, ALK and calcium. I believe alk and calcium need to be balanced in your tank. if calcium is high it will drive your alk down you cant have both, its the bowl of marbles theory if one goes up the other goes down. i often question some of the test kits out there. bring over a sample i have Tunze test kits for both and at least you can compare. I've also supplemented with bicarbonate in the past it doesnt last very long its needed daily to maintain

Link to comment
Share on other sites

Thanks Steve. When I have a free evening I'll see if you are available to test the water. It is looking like it won't be until Friday at the earliest. This is a full week.

 

I get the whole equilibrium thing (it is what I am teaching my kids at school right now). I can't see how my calcium can stay high, and my alk get so low as I am adding only alk to the system to balance it out.

 

dsoz

Link to comment
Share on other sites

Dennis test your PH and see what it is doing when the alk swings like that.

 

I have been keeping an eye on pH. Right now it is 8.2. It has not changed much all weekend long.

 

I don't have a Mg test kit. I am budgeting one test kit a month for the next couple of months. Next month it will be an Elos Calcium test, then after that it will be a Mg test kit.

 

dsoz

Link to comment
Share on other sites

Dennis let me know, if you have time i can bring them to your house thats no problem at all(whistle) not doin much else this week

 

 

 

yeah i have been having very high Ca and low alk for the past 2 weeks..my Ca is 600 and alk is 2 meq/L..i only do water changes and haven't dosed anything..and use seachem reef salt..

 

Jason I would look for some new test kits(scratch)

Link to comment
Share on other sites

Thanks for the offer Steve, you are AWESOME. My schedule is just very hectic with the kids doing everything and running all over. Friday or Saturday is my first break I will have. I can bring some water over to you then. :)

 

d

Link to comment
Share on other sites

Concentrate on being consistent with the test kit, that might be where some of your fluctuation are coming from....

 

Are you using the test tube line, or syringe to measure 5ml? I recommend using the syringe.

 

With the Elos kit, 1 drop=1 dkh with 2.5ml in the test tube (low resolution), and 1 drop=0.5 dkh with 5ml in the test tube (high resolution).

 

Now that I have my calcium reactor dialed in, I just use the low resolution to save test solution...If it turns yellow on the 10th drop, I know I am good to go!

Link to comment
Share on other sites

I am using the syringe, and putting in 5 ml. I am ending up with between 12 and 18 drops. On Saturday, after dripping the alk part of the 2 part solution all day long I got the alk up to 20 drops. But then on Sunday morning it was back to 14 drops, and Sunday afternoon it was down to 12 drops...

 

Now part of it could be that I was gone on vacation for a week and there was no dosing of two part for that time. But I don't see how it could get used up like that if the calcium is still high. I thought that corals used both the calcium and the carbonate at the same rate.

 

I understand that using 2 cups per gallon of water for both the calcium chloride and sodium carbonate is not the most accurate and balanced method of measuring out the chemicals, but I have the gut feeling that it is close. Maybe I should bring in my 2 part chemicals and test them in my lab to see how close to being balanced the BRS instructions are.

 

dsoz

Link to comment
Share on other sites

Anytime I have ca/alk issues, I do a 30-50% W/C.

 

I suspect a bad CA test kit.

 

Also, Ryan mentioned the low range dilution for the Elos kit. My kit is pretty darn accurate using that method and the kit last's 2x as long.

 

I haven't used BRS 2 part so I can't comment on that.

 

I just use Kalkwasser and occasionally add Turbo calcium, and Reef builder if my tests are off.

Link to comment
Share on other sites

 

Now part of it could be that I was gone on vacation for a week and there was no dosing of two part for that time. But I don't see how it could get used up like that if the calcium is still high. I thought that corals used both the calcium and the carbonate at the same rate.

 

dsoz

 

Hey, I'm no chemistry teacher, ;) but... as I understand it, alk can also be driven down by the addition of any acids, and/or by having a heavy bio-load (from decomposing waste, I guess). So, your alk is not necessarily going to fall consistently with your calc. You don't have a ton of fish in there, but you do have a pretty high density of corals. Could that be contributing to driving your alk down? The Elos kits should be good, but I would sure try to get a confirming test from someone else.

 

Also, if the readings turn out to be correct, you may look at trying something else as a buffer. I'll give you a couple of tablespoons of Seachem buffer and see if that helps. It has more than just carbonate in it, but I can't remember what all they list at the moment.

Link to comment
Share on other sites

Thanks all for the help, and the offers for help testing my water. But I have the problem solved. It was a bad test kit. Kilmca came over tonight and brought his calcium test kit and my tank tested 390 for calcium. Not 500. I was freaking out for nothing. No problems any more. Both calcium and alk are low, so I need to up my dosing schedule. I do have a fairly large load of corals, and they have been growing fast once I started dosing calcium and alk more often. I used to only add kalkwasser, but I am starting to like this two part mix. Someday I will have to graduate to a calcium reactor... Maybe after I win the lottery. :)

 

dsoz

Link to comment
Share on other sites

Thanks Steve. When I have a free evening I'll see if you are available to test the water. It is looking like it won't be until Friday at the earliest. This is a full week.

 

I get the whole equilibrium thing (it is what I am teaching my kids at school right now). I can't see how my calcium can stay high, and my alk get so low as I am adding only alk to the system to balance it out.

 

dsoz

 

 

Dennis:

 

Have you looked at the articles by Randy Holmes-Farley? He has written a number of articles describing the kind of issues that you describe. Here is one that I find useful:

 

http://web.archive.org/web/20021127040526/http://www.advancedaquarist.com/issues/nov2002/chem.htm.

 

Bob

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...