Raising just alk?

[ncdubz]

I've noticed some slow growth lately and some new corals not acclimating well. So I decided to start testing. Turns out my alk is low but everything else seems in line. Mainly lps and some sps.

My question is what is the best way to raise just my alk? I read the article by Randy and I'm leaning toward adding .25 teaspoons of sodium bicarbonate twice a day until I hit 9-9.5 alk ( I use reef crystals salt and it tests in that range). Or I could do several large water changes over the next week or so. Not sure which way would be best, any advice?

Parameters
40b with 20l sump
1.025 sg
Alk 5.1-5.4 dhk
Ca 430
Mg 1350
Ph 8.2

Currently doing 5g weekly wc.

 

[Why-Me]

I've noticed some slow growth lately and some new corals not acclimating well. So I decided to start testing. Turns out my alk is low but everything else seems in line. Mainly lps and some sps.

My question is what is the best way to raise just my alk? I read the article by Randy and I'm leaning toward adding .25 teaspoons of sodium bicarbonate twice a day until I hit 9-9.5 alk ( I use reef crystals salt and it tests in that range). Or I could do several large water changes over the next week or so. Not sure which way would be best, any advice?

Parameters
40b with 20l sump
1.025 sg
Alk 5.1-5.4 dhk
Ca 430
Mg 1350
Ph 8.2

Currently doing 5g weekly wc.

Personally I use BRS soda ash, which is pharmaceutical grade sodium bicarbonate. What I buy is the 1 gallon mix and I mix the whole package into their one gallon jug and you're ready to dose whatever you need to, like the display tank or wc holding tank etc. I don't even dose directly into the tank anymore. Just keep my WC brute can at the dKh that I want and when my WC is complete the display tank is back up to where I want it to be.
I have a 40b with roughly 13gal in the sump and do 10gal weekly WC.

 

[redfishbluefish]

It appears water changes alone will not maintain alk (and eventually calc). You'll need to start dosing. Short term, yes, sodium bicarbonate (baking soda) can be used to raise alk. But long term, you'll need to look into both alk and calc dosing. You mentioned Dr. Randy Holmes Farley.....he's put out a DIY paper on dosing that can be found HERE.

 

[BeejReef]

That's very low alk. Actually hard to get it that low. Just to be safe, I'd def have a second test or an LFS confirm that before any corrective dose. Beautiful params otherwise. If corrective dose is confirmed as needed, def space it out over several days to a week or so.

 

[ncdubz]

Thanks for everyone's advice! Going to give that link a good read as well.

I thought it was suspiciously low too. Tested using both salifert and red Sea kits. Also measured a sample of mixed wc water with salt and everything agreed. In terms of speed im going to start at +.25dkh in the morning and+.25dkh in the evening per day and see how everything responds.

 

[cilyjr]

soda ash, which is pharmaceutical grade sodium bicarbonate

This is incorrect. Soda ash is sodium carbonate not bicarbonate not a huge deal except baking soda (sodium bicarbonate) may produce a small temporary drop in ph until the extra carbon expelled.

 

[GregDaKeg]

I've noticed some slow growth lately and some new corals not acclimating well. So I decided to start testing. Turns out my alk is low but everything else seems in line. Mainly lps and some sps.

My question is what is the best way to raise just my alk? I read the article by Randy and I'm leaning toward adding .25 teaspoons of sodium bicarbonate twice a day until I hit 9-9.5 alk ( I use reef crystals salt and it tests in that range). Or I could do several large water changes over the next week or so. Not sure which way would be best, any advice?

Parameters
40b with 20l sump
1.025 sg
Alk 5.1-5.4 dhk
Ca 430
Mg 1350
Ph 8.2

Currently doing 5g weekly wc.

I am in the same boat. My new tank 4 months old consumes alk and a bit of mag every two weeks. I have to dose 12Ml of alk every week.
I only have 2 small zoa frags. I try to maintain 9 alk (salt mix) 1350 mag. Calc stays around 420. 60 gal tank. New tank. I have no idea why my alk is being consumed so fast compared to calc. Fritz salt mix @9.1 alk. 10 gal weekly water changes. I cant afford all the test! Lol. Hanna alk & calc. Red sea mag test kits btw.