Low Alk high Cal

[b.reef]

I’ve been having trouble keeping my alkalinity up and my calcium down. I do weekly water changes at 15-20% and my tank is a 13.5g fluval evo. The tank is a little over a year old and I use instant ocean reef crystals. It seems like every water change my alk drops more and more. I guess my question is will dosing Alk be the fix to my problem?? Never had to add anything other than weekly water changes. I use hanna checkers as well. Thanks in advance!

Salinity- 1.025
Alk- 4.5
Calcium- 530
Magnesium-1320

 

[liddojunior]

Full tank shot would help.

Uh Alk 4.5 is really low, I wouldn’t think it would be that low.

How do you make your water ? It might precipitating out the Alk.

Your pH might be really low too

 

[b.reef]

This is the lowest it’s ever been. It seemed like every week it would drop about 1-2ppm even with water changes. I have a 10 gallon garbage can with a power head, heater, and sealed lid when mixing.

I did not check PH but will order a test kit

 

[b.reef]

Full tank shot would help.

Uh Alk 4.5 is really low, I wouldn’t think it would be that low.

How do you make your water ? It might precipitating out the Alk.

Your pH might be really low too

 

[Randy Holmes-Farley Verified Community Expert]

Water changes cannot generally maintain alk unless the salt mix has an alk much higher than your tank, and the demand is very low.

I'd just boost the alk with some baking soda dissolved in RO/DI.

https://reef.diesyst.com/chemcalc/chem_calc3.html

 

[b.reef]

Water changes cannot generally maintain alk unless the salt mix has an alk much higher than your tank, and the demand is very low.

I'd just boost the alk with some baking soda dissolved in RO/DI.

https://reef.diesyst.com/chemcalc/chem_calc3.html

Appreciate the feedback! Would I be fine with just putting the baking soda right in my auto top off?

 

[Randy Holmes-Farley Verified Community Expert]

Appreciate the feedback! Would I be fine with just putting the baking soda right in my auto top off?

If that’s the only thing besides water, yes.

 

[chrspher]

Question on this tread.. I got am Ak up to 10.7 dkh the checked it today and its back down to 5.6 where is this going ?

 

[Uncle99]

Question on this tread.. I got am Ak up to 10.7 dkh the checked it today and its back down to 5.6 where is this going ?

What’s MG?
Low low MG can cause tests results to vary.
Should be 1350-1400ppm

 

[chrspher]

What’s MG?
Low low MG can cause tests results to vary.
Should be 1350-1400ppm

Not sure I'll check it next

 

[chrspher]

1115 ppm

 

[Randy Holmes-Farley Verified Community Expert]

I

1115 ppm

I suspect that is test error or low salinity. It would take a long time of high calcium dosing to drive magnesium that low.

Can you describe that tank history?

What do you think salinity is?

 

[chrspher]

I

I suspect that is test error or low salinity. It would take a long time of high calcium dosing to drive magnesium that low.

Can you describe that tank history?

What do you think salinity is?

Salinity is 1.025 Had a new sump put in a year or so ago and the tank when south tore down restarted has 3 clowns and two Damsels That seem to be fine been afraid to add anything until chem. is right Just got some chaeto To see if it will grow have a full rodi setup with 0 tds

 

[chrspher]

Salinity is 1.025 Had a new sump put in a year or so ago and the tank when south tore down restarted has 3 clowns and two Damsels That seem to be fine been afraid to add anything until chem. is right Just got some chaeto To see if it will grow have a full rodi setup with 0 tds

Testing with a Hana Marine Master

 

[Randy Holmes-Farley Verified Community Expert]

I’d ignore magnesium testing in this scenario.

 

[chrspher]

Ok

 

[chrspher]

Just need to figure out why my Ak keeps drooping

 

[Airedale Reef]

Appreciate the feedback! Would I be fine with just putting the baking soda right in my auto top off?

I use Instant Ocean RC as well. I have been dosing Kalkwasser through my ATO. Seems to help boost my dKH, as well as PH.

 

[Randy Holmes-Farley Verified Community Expert]

Just need to figure out why my Ak keeps drooping

It’s not clear how fast it dropped or what is in your tank. Can you give more info?

 

[Uncle99]

1115 ppm

That checker is always wrong.
The sample size is too small.
Hanna makes some good checkers, IMO, that’s not one and is same as their CA, wide fluxes in results.

I’d just recheck that with salifert or Aquaforest, both easy to see the colour change.

When my MG was low, my Alk tested low.


Then if still low, bump that MG up, and retest.