Alk decreasing .4 Dkh day no coral only rock sand a few fish

[Chris Spaulding]

New tank 240+gallons cycle complete only dry rock and sand with a few fish. Alk is decreasing about .4 Dkh a day calcium holding steady at around 420. There are no coral just some diatoms as part of the uglies.
Do I just keep dosing Alk until things stabilize?

 

[KrisReef]

New tank 240+gallons cycle complete only dry rock and sand with a few fish. Alk is decreasing about .4 Dkh a day calcium holding steady at around 420. There are no coral just some diatoms as part of the uglies.
Do I just keep dosing Alk until things stabilize?

Yes. Dry rock will eventually absorb all it needs and the usage will drop off.

 

[Miami Reef]

It’s not necessary to test for alkalinity during the cycling stage if there aren’t any corals.

You can maintain alk from 7-11dKH, but it’s probably best to stay near the lower range with new tanks since precipitation is more likely.

 

[Miami Reef]

Yes. Dry rock will eventually absorb all it needs and the usage will drop off.

Dry rock doesn’t “absorb” alkalinity.

It can initiate some precipitation of calcium carbonate. Not usually a big issue. More of a concern with sand.

Just let the alk remain where it wants to be for a few weeks. Once you decide to add corals, you can maintain alk levels.

Having some fish in the tank will prevent precipitation by having some phosphate and organics from the feeding.

 

[KrisReef]

Dry rock doesn’t “absorb” alkalinity.



Just let the alk remain where it wants to be for a few weeks. Once you decide to add corals, you can maintain levels.

Having some fish in the tank will prevent precipitation from the extra phosphate and organics from the feeding.

I suppose you are right about that.

 

[GARRIGA]

Nitrification consumes alkalinity. Carbon dosing or macroalgae can return it absent a water change. In other words. Corals not the only consumers of alkalinity which is expected to drop during cycling.

 

[Randy Holmes-Farley]

The dry bare rock can act as a seed crystal for precipitation of calcium carbonate until it gets a protective layer of organics, bacteria, phosphate, and magnesium.

Even though both alk and calcium are consumed, it would take a while to see the balancing calcium drop of less than 3 ppm per day.

 

[Pete2020]

Hello, sorry to jump in on this post. Im facing the same issue with alk decresing about .1dkh per day. Calcium sitting steady at 450ppm. Do i just wait it out and keep up with water changes or dose a bit of soda ash to bring it up closer to where my fresh salt water would be? It dropped off quite a bit compared to freshly mixed saltwater. No corals yet. Tank is 7 months old.

 

[Randy Holmes-Farley]

Hello, sorry to jump in on this post. Im facing the same issue with alk decresing about .1dkh per day. Calcium sitting steady at 450ppm. Do i just wait it out and keep up with water changes or dose a bit of soda ash to bring it up closer to where my fresh salt water would be? It dropped off quite a bit compared to freshly mixed saltwater. No corals yet. Tank is 7 months old.

A little dosing would be fine.