Does anyone does Kalk with 2- part to maintain PH?

beachsidereefer · Jan 13, 2016

Hi Everyone.

Currently I use programmable auto dosers to drip 2- part BRS salts into my 200G DT.

I'm seem to have two issues I can't seem to solve.

1. Every week I test ALK and CA and it's always low. Using the BRS 2-part calculator I'll add the proper quantity of two part solution to bring both levels back up but the following week the numbers are back down again. To try to address this I've tried to increase the amount of two part I'm auto dosing but it seems like I hit a certain point and then I start seeing a lot of calcium precipitation in my wet/ dry, protein skimmer, pumps etc.
2. My PH is always low ranging from 7.9 to 8.1. I've tried various buffers that will raise PH to 8.3/ 8.4 but 24 hours later it'll be back down to the lower value I started at. One thing I did try was piping in fresh air from outside into my protein skimmer but it didn't have any effect on my PH.

I test for MG once once a week along with ALK and CA and it's always within normal range. Also I do 30% water changes once a month using Red Sea Coral pro salt and RO/ DI water. As far as corals I have a pretty light load of softies so I believe it's probably the coraline algae that's sucking up the CA/ ALK.

So my question is would dosing Kalk solution using a auto doser help me maintain a higher PH and stabilize my declining ALK and CA values?

cmcoker · Jan 13, 2016

I wouldn't worry about the pH, those buffers will add to your alkalinity as well. Maybe that is contributing to your precipitation.
What numbers are you trying to maintain?

Randy Holmes-Farley · Jan 13, 2016

The buffers are less effective than just using the BRS two part with respect to pH raising.

Many people have to dose alkalinity every day, or several times a day, so depletion after a week is certainly not unexpected. Coralline can take up a lot!

Your pH is fine, but using limewater (kalkwasser)every day instead of some of the two part is certainly a fine way to go.

Some people do it, but more so for people using CaCO3/Co2 reactors which depress pH.

beachsidereefer · Jan 13, 2016

I follow RHF's recommended parameters for ALK and CA http://reefkeeping.com/issues/2004-05/rhf/

So I try to maintain 430-440 PPM CA and 9 dKH. I check parameters weekly so the cycle is pretty consistent. I'll test and my CA will be some where between 380-390 and a 6 for dKH. I'll use the BRS calculator and add enough CA solution to bring up that value back up to 440 then I'll wait about an hour and bring the ALK value up to 9 first by adding seachem reef buffer to bring up the PH and then reef builder to hit my 9 dKH number. I do this by testing ALK after I do the first dose of builder. If I'm not at 9 then I'll do a second dose which usually does the trick.

beachsidereefer · Jan 13, 2016

just to add I follow the Seachem directions on how much to dose for 200 g of water

beachsidereefer · Jan 13, 2016

Randy Holmes-Farley said:
The buffers are less effective than just using the BRS two part with respect to pH raising.

Many people have to dose alkalinity every day, or several times a day, so depletion after a week is certainly not unexpected. Coralline can take up a lot!

Your pH is fine, but using limewater (kalkwasser)every day instead of some of the two part is certainly a fine way to go.

Some people do it, but more so for people using CaCO3/Co2 reactors which depress pH.

Hi Randy,

Thank you for your reply! Question; I use a auto doser for CA and ALK, do you have any theories on why when I try to dose more to maintain a constant level I seem to hit a wall and start to see participation clogging up my equipment? Just to add I have my dose lines configured so the 2 part solution is going into the tank over one of my returns instead of into the sump.

Randy Holmes-Farley · Jan 13, 2016

beachsidereefer said:
Hi Randy,

Thank you for your reply! Question; I use a auto doser for CA and ALK, do you have any theories on why when I try to dose more to maintain a constant level I seem to hit a wall and start to see participation clogging up my equipment? Just to add I have my dose lines configured so the 2 part solution is going into the tank over one of my returns instead of into the sump.

Which equipment? The doser, or in the tank?

DLuce510 · Jan 13, 2016

Are you dosing equal amounts of two part? Some times if your dosing more Alk then Ca it will rise then drop suddenly with a lot of precipitation.

cmcoker · Jan 13, 2016

Are you both dosing at same time? Or alternating?

kevindo123 · Jan 13, 2016

What is your magnesium level?

beachsidereefer · Jan 14, 2016

Randy Holmes-Farley said:
Which equipment? The doser, in the tank?

Pumps, skimmer, heater etc. basically all the stuff connected to sump will start to see CA build up once I hit a certain dosing point.

beachsidereefer · Jan 14, 2016

kevindo123 said:
What is your magnesium level?

I test it bi-weekly, it's never dropped below 1300 and I've never had to does MG. I believe my water changes are sufficient to keep this parameter up

beachsidereefer · Jan 14, 2016

cmcoker said:
Are you both dosing at same time? Or alternating?

it's staggered with a 10 minute separation in dosing.

beachsidereefer · Jan 14, 2016

DLuce510 said:
Are you dosing equal amounts of two part? Some times if your dosing more Alk then Ca it will rise then drop suddenly with a lot of precipitation.

Yes, I dose in equal amounts. spent a lot of time calibrating each pump so it would be equal!

Randy Holmes-Farley · Jan 14, 2016

Some precipitation is normal.

The things that lead to more are high alk, calcium, and pH, and low magnesium (and a few others such as organics, phosphate, etc.). Low flow amd mixing near the addition point will also increase local precipitation, as will dosing pumps adding alk too fast.

What alkalintiy are you trying to target?

beachsidereefer · Jan 14, 2016

Randy Holmes-Farley said:
Some precipitation is normal.

The things that lead to more are high alk, calcium, and pH, and low magnesium (and a few others such as organics, phosphate, etc.). Low flow amd mixing near the addition point will also increase local precipitation, as will dosing pumps adding alk too fast.

What alkalintiy are you trying to target?

I'm shooting for 430-440 PPM CA and 9 dKH ALK

Randy Holmes-Farley · Jan 14, 2016

beachsidereefer said:
I'm shooting for 430-440 PPM CA and 9 dKH ALK

That wouldn't seem to be a problem, assuming your kits are working right.

You might watch it when the alk doses and look for the normal local precipitation (while cloudiness in the water) of magnesium hydroxide and how fast it dissipates.

GainesvilleReef · Jan 14, 2016

Back to the original question. I do dose Kalk and 2 part. I started with 2 part dosing and due to my basement tank location I had ph values 7.9 to 8.0. I switched to dosing saturated kalk solution with a dosing pump. After I reached the max amount I could add to the tank due to evaporation limits I started dosing 2 part on top of the kalk. My current ph values are 8.1 to 8.2. In my case about half of that improvement is due to the kalk. The other half come from my use of an algae turf scrubber. I know this because the ATS light failed and I noticed by ph dropping to 8.0 to 8.1. When I fixed the light it returned to 8.1 to 8.2. In my opinion the coral grows slightly faster nearer to 8.2. But my tanks were also doing fine at 7.9 to 8.0. So I am actually doing 3 things to improve the ph. Kalk, Sodium Carbonate as my alk part of 2 part and an ATS. All three contribute to a higher ph but main purposes are for something else and I would do anyway.

GainesvilleReef · Jan 14, 2016

Also, for kalk and 2 part to raise the ph you need significant alkalinity consumption by the tank. It's the rate that you add these versus that rate that CO2 re-enters the water that determines any ph affect. So neither of these methods will change the ph much on a new tank. But once the coralline algae and stoney coral start growing you will need to add more and more to maintain alk and ca. When this happens you will start to see positive effects on ph.

Randy Holmes-Farley · Jan 15, 2016

GainesvilleReef said:
Also, for kalk and 2 part to raise the ph you need significant alkalinity consumption by the tank. It's the rate that you add these versus that rate that CO2 re-enters the water that determines any ph affect. So neither of these methods will change the ph much on a new tank. But once the coralline algae and stoney coral start growing you will need to add more and more to maintain alk and ca. When this happens you will start to see positive effects on ph.

Yes, that's a good point that I think some people misunderstand.