Alk Problems ?

[Reefist]

What can eat up Alk? My dKh was 6.4 so I added some buffer watching the ph( no movement). Recalibrated my Ph meter. Checked Mg 1410 ,Calcium 405. Checked Alk 12 hrs later, 5.0 dKh. This has been going on for some time now. Everything looks good but this bugs me. I did a 40 Gallon water change on a 210 with Reef Crystals. Checked that water and that was 11.4 dKH. but the only time my reading goes up is right after the water change. I have a salifert test kit, Red Sea Pro, and now I just got a Hanna Checker.All the same give or take not worth mentioning. I really would like to figure this out. Thanks for any help
Tom

[mbg75]

U running GFO? Sometimes that might drop your Alk

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[Reefist]

No not right now. But I was 2 months ago but I've done many 40G water changes since then. This makes me nuts

[seldin]

Not sure this helps, but when I switched brands of salt, my parms changed. Seems like my new salt really had a very high amount of calcium and with my dosing it went too high. Took a bit to lower it. And with new brand, seems Alk was on the low side...

So maybe you might want to measure a new water change salt bucket to see what's going in the tank before it gets in there. Parms on new salt, may be not where you think they should be.

[Reefist]

Not a bad idea but I just purchased 4 -200G mix boxes of reef crystals but the alk on fresh mix was 11.4 dKh. Why would it go down when adding buffer?
Tom

[DrHarryLopez]

what type of corals are you keeping?
Are you dosing?
How much are you dosing daily? Ca, Alk
You will most likely need to do a dose adjustment of Alk. maybe even bump up the Ca just to have a buffer in case your numbers continue to drop.
Check the chem calc (http://reef.diesyst.com/chemcalc/chemcalc.html)

When my corals have their growth spurts the first thing that drops is my alk, then my Ca

first thin i do is double ck my test kits, then I do a dose adjustment and up my daily dosage. I check my numbers every two or three days.

Hope this helps you out.

[Reefist]

Funny you should say that cause I have had quite a growth spurt and BTW all sps. I've been reluctant to hook up my ca reactor since it had caused me so many problems in the past and since my CA was around 400( something I couldn't seem to get with my reactor) but I'm rethinking it. I'm just trying to figure why if I add buffer (Kent Superbuffer dKH) does my alk go down. I do know that it can preciptate but at a ph of 8.1. And yes I have calibrated my meter twice this month to be sure.When I do a water change and the Alk is normal (7.5 dKH ) then the ph stays around 8.3 for a couple of days but it just drops down after that . I have tried to drip Kalk and both pH and Alk drop.Crazy right. I've been in the hobby since 95 and always had problems like this. I even thought it was my RO once so I bought a new one. There is something missing in my water(ionically I think). Just don't know about chemistry
Thanks
Tom

[username in use]

I have read reports of low Magnesium causing a drop in Alk, not sure on the validity of it, buy it might be worth testing your mag just to see.

[Reefist]

Oh theres alot of valitity in it. But as in my original post Mg is 1410. and thats with a new Sailifert testkit.
Thanks
Tom

[username in use]

oops, missed that in the first post.


Here's a random thought that may have zero bearing. Since Sodium Bicabornate is a base, it could be being depleted by something acidic. Is there anything on line, or being added that has some kind of acid in it?

[Reefist]

Yeah I though of that. I did 3 months back try Biopellets but I got tissue recession in the middlle of some of my corals so I stopped it but that was again many many water changes ago. I checked parameters again and Ca was 495,Alk 6.0, Mg 1420. I do use zeo bak(3 drops / week )and zeo coral snow randomly but I don't think that would make it acidic. Thanks for thinking it thru. At least I get some comfort that I'm thinking straight.
Tom

[cdamiano]

If you are using a dosing pump, did you try increasing the amount of Alk you are dosing from your dosing pump in conjunction with trying to raise the Alk with the buffer? Based on what you described, it sounds as though your dosing pump isn't keeping up with your demand. Either that or your test kit is bad.

[Reefist]

Hey Chris ,
thanks for your response.Just so you know I have three testkits Sailfert, Red Sea Pro and I just got a new Hanna Checker Colorometer Alk tester. They are all in conjunction. I don't have a dosing pump but why would I need to just add alk regularly and how would it preciptate out with out raising pH? The more Kent super buffer I add the the lower the Alk reading and the higher the Ca. I figure it must preciptate out with out the pH rising but with all I read I can't find anything . Readings today after adding more buffer same as yesterday but alk down a little .{Ca 495,Alk 5.6, Mg 1420}

[username in use]

Try mixing up a gallon of fresh water. Test the parameters, then add some of the buffer to the water to raise the alk. (try and measure it based on what the instructions say will raise a gallon x amount). See where that gets you. Airate and circulate it with a powerhead for a couple days and then test again. Just to see whether its in the product, or the tank.