Alk Question

JoeSchmo45 · Dec 6, 2020

Hello R2R,

I have a Reefer 170 that has been cycled for about three months now. I added my first corals a couple days ago (zoa and two mushrooms). I've been monitoring parameters since I got the tank and noticed for about the past month that my alk drops pretty quickly (this was before adding coral). My alk has been dropping about .5 dkh a day. I purchased the BRS alk, cal, and mag pouches some time ago and started hand dosing just the alk because it's the only thing that appears to be changing. My calcium is 410-420 every time I test and magnesium is 1400. I've been dosing 10ml of the BRS alk each evening. That brings the alk up to 8.1. By the same time next day it's down to 7.6. By the way, I'm using the Red Sea testing kit

My questions - 1.) Is it okay to be dosing just alkalinity like this? Am I doing more damage than good? Should I dose less, more, or not at all? 2.) I've also got a bottle of Red Sea Reef Energy Plus Coral Nutrition. Is it okay to be dosing that a few times a week as well for the new corals?

My other parameters:

Amm - 0
nitrite- 0
nitrate - 0-5
phos - 0
sal - 1.025
temp - 78

Thank you!
Joe

cshouston · Dec 6, 2020

Any fish in there? Nitrification consumes alkalinity. Zoas and mushrooms aren’t building calcified skeletons, so they aren’t consuming it.

JoeSchmo45 · Dec 6, 2020

Yes, I should have added that! Two clowns, an orange spotted goby and a cleaner shrimp. That's all the inhabitants so far. Will be getting just one more fish eventually.

cshouston · Dec 6, 2020

JoeSchmo45 said:
Yes, I should have added that! Two clowns, an orange spotted goby and a cleaner shrimp. That's all the inhabitants so far. Will be getting just one more fish eventually.

That’s your culprit, then. The process of converting ammonia to nitrate destroys a certain amount of alkalinity per ppm of ammonia. I don’t have the numbers offhand. The alkalinity is only returned if the nitrate is denitrified through natural processes, such as conversion to nitrogen gas by anaerobic bacteria.

It’s fine to replace the lost alkalinity. Just keep an eye on all of your parameters, as you would, and you’ll be fine. As for the Red Sea reef energy, it’s probably unnecessary at this point and will just contribute to fouling the water over time. The zoas and mushrooms will be fine with just light and the nutrients created by your fish waste.

YankeeTankee · Dec 6, 2020

It is normal for alk to drop faster than calcium, that's how this works. It's roughly 3dkh for 20 ppm ca so I'd just keep dosing both. If you start seeing your ca shoot up then go alk alone.

cshouston · Dec 6, 2020

YankeeTankee said:
It is normal for alk to drop faster than calcium, that's how this works. It's roughly 3dkh for 20 ppm ca so I'd just keep dosing both. If you start seeing your ca shoot up then go alk alone.

Except there’s nothing in the tank that’s building a calcified skeleton. He only has a couple of mushrooms and a single zoa. It’s alkalinity loss due to nitrification. Adding calcium will just build up.

YankeeTankee · Dec 6, 2020

cshouston said:
Except there’s nothing in the tank that’s building a calcified skeleton. He only has a couple of mushrooms and a single zoa. It’s alkalinity loss due to nitrification. Adding calcium will just build up.

Gotcha, I quickly scanned the post, that sounds right! Keep that ratio in mind for futures though Joe

JoeSchmo45 · Dec 6, 2020

cshouston said:
That’s your culprit, then. The process of converting ammonia to nitrate destroys a certain amount of alkalinity per ppm of ammonia. I don’t have the numbers offhand. The alkalinity is only returned if the nitrate is denitrified through natural processes, such as conversion to nitrogen gas by anaerobic bacteria.

It’s fine to replace the lost alkalinity. Just keep an eye on all of your parameters, as you would, and you’ll be fine. As for the Red Sea reef energy, it’s probably unnecessary at this point and will just contribute to fouling the water over time. The zoas and mushrooms will be fine with just light and the nutrients created by your fish waste.