Alk drop without live stock?

[Kevinkmk]

hi everyone,

I just recently upgrade my old tank to a 91 gallon tank. The new tank is currently running 3 days with only live rocks. However, my alk has drop from 9.9 to 8.5 in three days with only live rocks. I’m wondering is it something normal? Currently I’m running BRS GFO and carbon (using recommend 1.4 cup GFO and 0.4 cup carbon), and protein skimmer. Is it because of the GFO? Any tips would help. Thank you!

Tank parameter
Cal 450
Alk 8.5
Mag 1500
Po4 0.04
No3 2

 

[Kevinkmk]

anyone?

 

[cracker]

I'm curious also, here's a bump

 

[Kevinkmk]

Bump

 

[nautical_nathaniel]

How stable has it been since it dropped?

 

[Crabs McJones]

It could be from the GFO, I've read elsewhere that GFO can cause calcium carbonate precipitation, which can effect calcium and alk levels. Have you tested your calcium levels ( i know its unlikely at this point as you have no corals) But that might be the cause.

 

[Kevinkmk]

The t

How stable has it been since it dropped?

The tank has just recently been setup from my old tank. So I do not have any data. My old tank is pretty stable.

 

[Kevinkmk]

It could be from the GFO, I've read elsewhere that GFO can cause calcium carbonate precipitation, which can effect calcium and alk levels. Have you tested your calcium levels ( i know its unlikely at this point as you have no corals) But that might be the cause.

I do have test all parameters. The calcium is the same, alk has drop, and mag has increase.

 

[Randy Holmes-Farley]

It is normal for their to be abiotic precipitation in reef aquaria that are almost always supersaturated with calcium carbonate (as is normal seawater). It happens in new salt mix containers as well. :)

Iron on the GFO and iron released to the water can accelerate it, as will lack of organic matter.

 

[Randy Holmes-Farley]

I do have test all parameters. The calcium is the same, alk has drop, and mag has increase.

You would be unable to detect reliably the calcium decline associated with a 1.4 dKH alk drop (being about 9 ppm).

The magnesium rise is just testing error.

 

[Kevinkmk]

You would be unable to detect reliably the calcium decline associated with a 1.4 dKH alk drop (being about 9 ppm).

The magnesium rise is just testing error.

Thank Randy! Will it keep dropping or is there way to make it stable?

 

[Randy Holmes-Farley]

Thank Randy! Will it keep dropping or is there way to make it stable?

The drop will typically go slower and slower as alk drops.

 

[Kevinkmk]

The drop will typically go slower and slower as alk drops.

Does it mean if I want to keep my alk at 9, I will have to be dosing 0.5 alk (same amount for calcium) everyday to keep it stable? Assuming I do not want it to drop

 

[Randy Holmes-Farley]

Does it mean if I want to keep my alk at 9, I will have to be dosing 0.5 alk (same amount for calcium) everyday to keep it stable? Assuming I do not want it to drop

Quite possibly, yes. Until you get creatures in it, I'd let it free fall and only boost it back once you have something in it that cares (a hard coral, etc.)...

 

[Randy Holmes-Farley]

See this post on new salt water:

https://www.reef2reef.com/threads/liveaquaria-salt-any-numbers-yet.329592/page-4#post-4277701

 

[Kevinkmk]

Quite possibly, yes. Until you get creatures in it, I'd let it free fall and only boost it back once you have something in it that cares (a hard coral, etc.)...

So after I add livestock (ie fish and snail) the alk wont drop that much? I’m planning to put corals in but I will quariteen my fishes for 30 days before add them back into the dt. So having only corals inside the tank, Will GFO remove the alk like what I’m currently having? Thanks

 

[Randy Holmes-Farley]

So after I add livestock (ie fish and snail) the alk wont drop that much? I’m planning to put corals in but I will quariteen my fishes for 30 days before add them back into the dt. So having only corals inside the tank, Will GFO remove the alk like what I’m currently having? Thanks

It might be faster or slower. :D

GFO is not removing alkalinity. It can, however, accelerate precipitation of calcium carbonate.

 

[Kevinkmk]

Thanks

 

[Kevinkmk]

It might be faster or slower. :D

GFO is not removing alkalinity. It can, however, accelerate precipitation of calcium carbonate.

You are correct! My salinity has drop to 1.023 from1.025 during two weeks. There is white salt precipatate in my sump. Any idea how can I fix this? Thanks

 

[Randy Holmes-Farley]

You are correct! My salinity has drop to 1.023 from1.025 during two weeks. There is white salt precipatate in my sump. Any idea how can I fix this? Thanks

You are not dosing anything in that area?