dKH and Alk are too high

[jteaster]

My dKH is 16.0 and my Alk is 5.7. I have been pumping Purple Up into the tank because I cannot get my calcium levels above 320. Also, I'm having to add quite a bit of buffer to keep the ph from dropping.

I think the ph and calcium problems are coming from the high dKH and Alk. Does anyone know how to lower dKH and Alk to the correct levels?

 

[twilliard]

A lot of water changes

 

[Boomer]

That is your first problem Purple-Up. It has raised more issues lately than any other additive. Stop using it it. Do a large water change and siphon the very top of the SB if you have one. Don't use it again. There are other and more effective forms of buffers and Ca++ additives we can use with out using his crap.

 

[jteaster]

I'll cut out the purple up for a while and do some water changes...we'll see what happens.

 

[Boomer]

I forgot

WELCOME TO REEF FRONTIERS !

 

[knowcrap]

I'll cut out the purple up for a while and do some water changes...we'll see what happens.

jteaster - I've been using Seachem products with good results: Reef Builder for Alk buffering and Reef Advantage Calcium for Ca (plus it includes Magnesium & Strontium). I have yet to get into anythink more complex such as a Kalk drip or Ca reactor to maintain Ca and Alk.

To stablize our tank I just tested Ca and Alk (using Salifert tests) on a daily basis adding suppliments (according to directions) to maintain Alk of between 10 and 11 and Ca at 400 to 410. It took a couple of weeks to get a good system where I know what to add when...with occasional "spot" tests to make sure we're maintaining the dialed in levels as we increased the coral load.

As far as Purple Up goes, I've never used it and view suppliments like that as more bad than good...a stable tank should produce Coraline algee without the need to suppliment it...in ours some rock is getting it's 11th or 12th (or 50th. who knows now) coating on it...tank is about 1 year old.

After two years I believe that simplicity is the key...maintaining a complex system does not require insane complexity...just a little science, patience and reading...good luck!

 

[returnofsid]

I'm confused....lol. You mention your dKH AND your Alk. dKH is a measurement of Alk. Alk is measured, normally in either dKH or Mq/l. I also second what's been said about Purple Up. I used it for awhile on my first reef tank. It's not only useless, it causes tons of problems. There's a couple links in my signature that may be very helpful to you. One is for recipes for Ca, Alk and Mg supplements that are made with easy to obtain chemicals and ingredients. The other is for a great Reef Chemistry Calculator to help you figure out how much of each supplement to dose to get balanced and keep your levels where you want them!!

 

[matts125]

what does your magnesium test at? it sounds to me that your whole systems water chemestry is out of whack, if your mag is low then it is almost impossible to get your calcium to raise, I say test your mag and if it is below 1300 then raise it to 1350 and then start dosing straight calcium chloride to raise your calc...

Most importantly do a couple large water changes first!!!

Matt

 

[jteaster]

Thanks Matt. I agree the chemistry is just out of whack. I'm currently doing some large water changes to get the alk and KH down to normal levels. I'm going to let it settle then for about a week and address the low ph. After ph and alk/KH have stabilized I will test magnesium and address the calcium problem.

Things are looking a little better now already. Cal. is still at 300, but alk has dropped from 5.7 to about 4.3 and KH from 16 to 12dKH. The ph is 7.8, but I will get to that when I fix alk and KH.

 

[Boomer]

jt

Your biggest issue is that very high Alk. It is pulling down the Calicum and if the magnesium is also low it will be even worse. Also, whose test kits are you using, something I was going to bring up. I do not really buy 300 ppm calcium and think it is kit error or testing error. I hope you are not using Red Sea kits.

There is not reasaon to measure both Alk and dKH they are the same thing.

5.7 to about 4.3 and KH from 16 to 12dKH

5.7 x 2.8 = 16, 4.3 x 2.8 = 12 or 16 / 2.8 = 5.7 and 12/2.8 = 4.3

1 meq / l Alk = 2.8 dKH

As far as the pH goes there can be a number of reason but almost always it is high room air CO2 or overfeeding producing CO2.


Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

 

[jteaster]

Boomer,

I measure both simply because I'm using a Salifert alk/KH test and the reading gives you both...so I list them both. I've been using an Aquarium Pharmaceuticals test for calcium. Is this a good kit or should I try something else?

My plan is to do one more water change today...this should bring my alk to under 3. I'm going to let it rest for a few days and then add ph buffer to get the ph back up. It also raises the alk some, but hopefully not too much. In theory, that should stabilize ph and then I can address mag and cal problems. What do you think about that?

 

[scytale]

(My $.02)

Test kits = salifert, salifert, Salifert!

If the "pH buffer" youre using is a dry, white powder...DON'T add any more pH buffer! (most likely it's just baking soda + "ingredient X")
And adding baking soda to your tank will quicly RAISE YOUR ALK again.
(And it doesn't take much baking soda to raise your alk--just a few tsps will raise even big tanks...)

Get yourself a (salifert) MG test kit--and test your Mg levels first.

If your Mg level is less than 3x your CA level--then as long as your Mg level is low...you're going to continue to have problems maintianing your CA/ALK in balance no matter how much buffer you addd!

Also what time of day are you testing your pH? (pH will swing lower at night/early morning, before the lights come on....)

 

[Boomer]

It sounds good what you are doing

 

[jteaster]

Okay, here's an update of what's going on...

My alk is down to 3.88 thanks to the water changes and ph has stabilized at 7.8. That's a little lower then what I want but thanks to "Low ph: Causes and Cures" I know that it's because of CO2 in the water. My next hurdle is magnesium. Right now it's at 975 so I'm pulling it up with Reef Advantage magnesium.

After I get the mag to 1300 I'm thinking of doing a kalkwasser drip to dose calcium and bring up the ph.

 

[Boomer]

OK, looking better and your plans sound good.