Soda ash for tanks that drop 2+dkh a day bad?

[Miami Reef]

For those tanks that drop more than 2dkh, is it better to switch to sodium bicarbonate?

Will dosing once a day of soda ash to raise 2dkh be bad for the tank?

 

[Jekyl]

For those tanks that drop more than 2dkh, is it better to switch to sodium bicarbonate?

Will dosing once a day of soda ash to raise 2dkh be bad for the tank?

If really dropping 2dkh in a day I would use a doser set to multiple times a day. Raising 2dkh all at once is not a good thing.

 

[elysics]

2° dKH is way past the point where manual dosing makes sense.

What are you going to do if you can't be bothered one day, or accidentally do it twice? Let your corals die?

 

[blasterman]

My 20L drops 2dKH a day because its jammed full of SPS. More if I keep the pH up. Because alk consumption is not consistent (,small tank syndrome) Ive pulled my doser offline. I could/should rig my doser for 1dKH supplement per day and manually dose the difference, but I don't want to do that yet. Other priorities.

Is it ideal? No. Does it hurt coral? Nope. It likely slows down growth because of the low side of the dip, but I'm not in a race and I'm pH locked anyhow. Ive also forgot to manually dose many times and alk just drops a bit more and grinds to a hault around 6.5. If i didn't dose for a week i would have issues.

Keeping dKH at an average over 24 hours is whats important along with not adding automation that not 100% inline with tank goals. Also, not clear if the OP is having alk dives due to coral growth or just a young tank with establishing biology.

I don't see a difference between manually dosing baking soda or soda ash provided the OP keeps the 24 hour average the same. Works for my tank.

 

[RobB'z Reef]

Have you looked into a calcium reactor?

 

[Auquanut]

Unless dosing soda ash is sending your PH through the roof, I wouldn't think that switching to sodium bicarbonate is absolutely necessary. If I'm not mistaken, conventional wisdom has always dictated that more than a 1 dKH increase in Alk at one dose is a bad thing. Particularly for the more sensitive corals. Can't say if it's true. I've never increased my Alk more than .5 dKH per day even after a doser malfunction.

I will say that if the system is actually consuming 2 dKH per day, an autodoser may be in order. If your corals are truly consuming that much alkalinity (and presumably a commensurate amount of calcium), I would think that spreading the doses over multiple doses per day would have a positive effect on your corals. Also, I would expect less precipitation with less Alk/Cal being dosed at one time.

I autodose 200 ml of BRS soda ash and calcium chloride solutions daily in my 125 coral dense mixed reef, spread over 12 doses each scheduled on alternating hours. Seems to be working.

On the other hand, if you're dosing far more Alk than Cal solutions, there may be another issue.

 

[Randy Holmes-Farley]

For those tanks that drop more than 2dkh, is it better to switch to sodium bicarbonate?

Will dosing once a day of soda ash to raise 2dkh be bad for the tank?

That switch will likely reduce demand, both by lowering coral growth and lowering abiotic precipitation.

If abiotic precipitation is a problem, that may be worth doing.