Help. Ca = 550 Alk = 13.6dKH

[PotysGSXR]

Hello everyone.

I've had my tank set up for about 4 months now and I cant seem to get my Ca and Alk down. I used Tropic Marin salt until last week when I did a 20% water change with Reef Crystals as I'm slowly changing to the latter. My tank is 24g and all other params are great but Ca and Alk.

I read that if they're both high just leaving the tank be will lower the Ca and Alk on its' own but it's still sky high after 4 months. Anyone know what I can do in this case? Thanks in advance.

Paul

 

[MCsaxmaster]

I'd get a double check on both of those parameters with different test kits, to ensure those values are real.

If the same results are returned, you might want to consider doing a water change with a lowish calcium salt (e.g., Instant Ocean). Otherwise, you could just wait out a decrease in calcium and alkalinity. Since calcium is relatively more elevated than alkalinity, you'd need to supplement just alkalinity for awhile. As a guideline, for every 2.8 dKH of alkalinity you lose (= 1 meq/l) calcium should drop by ~20 ppm. So, for example, if you supplement nothing for a few days and the alkalinity drops down to 8 dKH you will have lost ~5.6 dKH of alkalinity. The calcium should have dropped by ~40 ppm (to 510 ppm). If you bump alkalinity up to 10.8 dKH and let it drop back 8 dKH again calcium will drop ~490 ppm. Do it again and calcium will drop to 470 ppm, etc.

Realize, however, that there is error involved in both the calcium and alkalinity measurment. These changes are more readily measurable in terms of change in alkalinity than they are in change in calcium since there is a large background concentration of calcium in sea water that is hard to resolve against but a much smaller alkalinity value. Hence, you can measure a change in alkalinity long before you can measure a change in calcium simply as an artefact of the testing methods.

Good luck,

Chris

 

[PotysGSXR]

Thanks for the advice Chirs. I think for now, I WILL have to wait it out even longer to see what happens.

It seems that normally, if calcium is high, then alkalinity is low and vice versa, but in my case they're both high and I'm not fully understanding why. I just hope that with a bit more time, things will settle.

I'm also going to try and change my top off. That might help.

 

[Billybeau1]

What do you mean change your top off.

Top off should be fresh water only. No salt.

Your numbers are a bit high but not earth shattering.

Do you know what your s.g. is and how do you measure. Also, what brand test kits for calcium and alkalinity ?

 

[bertoni]

I agree that those numbers are only a bit high. I wouldn't expect any problems.

 

[PotysGSXR]

By changing my top off, I meant changing the source of the water. I use RO/DI but I'm wondering since the water itself is very high in alk/ca. If it is, I guess I should buy bottled water.

I use Salifert for all my test kits and to measure salt, I use a refractometer.

It's good to know that it's not too high. I'm wondering what's killing some of my corals then.

 

[tmz]

You may wish to test the tds(total dissolved solids) on your ro/di water with a tds meter which can be had for about $20 to be sure it's working properly and not passing impurities to your tank which may be harming some of your corals. I don't know of any reason ro/di water would have significant if any calcium or alkalinity.If your ro/di unit is working proerly I would not change to bottled water.

 

[reefdawg7]

Try using different test kits. Parms seem high.
Also stop supplementing and see if your parms go down.

 

[PotysGSXR]

I've never supplemented yet. And I will try using different test kits as it DOES seem pretty high.

 

[RBU1]

Those readings are nothing to be concerned with. Some people would love to have readings like that. I would just let the tank eat it up.

 

[Billybeau1]

If you water params are good, which I think they are, I would then turn to lighting, water flow etc.

 

[tigerarmy40]

go to your lfs and have them test as well, could be yoru kits!?

 

[jdieck]

In case you missed it, your RO/DI water should not have any calcium or alkalinity in it. Look at your system filters for replacement or missed conections (You may have the product and waste lines trasposed in the wrong membrane outlet) or at where you purchase the RO/DI water from

 

[PotysGSXR]

Just tested my ro/di. its fine. its really good water actually. So I tested my salt, and it's fine as well. Im not sure what it is, but as far as my corals dying (my brain is now bleaching as well) I think it really might be the lights.

 

[PotysGSXR]

<a href=showthread.php?s=&postid=13191259#post13191259 target=_blank>Originally posted</a> by jdieck
In case you missed it, your RO/DI water should not have any calcium or alkalinity in it. Look at your system filters for replacement or missed conections (You may have the product and waste lines trasposed in the wrong membrane outlet) or at where you purchase the RO/DI water from

You're right. When tested, I found that my ca was almost zero and my alk was very very low (but it did come up in the readings)