alk too high

[melypr1985]

My corals looked unhappy so I had my water tested by my lfs. Full battery of tests. Everything tested within normal limits. My alk was 11 or12, which i'm told is the high side of normal. I don't dose anything at all, just water changes using lfs water. He tested their water and their alk was at 9. What would cause it rise? How do I make my corals happy again? Thanks!

 

[Rob&Gab]

How old is your tank?

Also what test kits are you using? And what's your cal and mag at?


And what lights your running?

 

[leptang]

Tap water.... dont use it for topping salinity. RO/DI system is the way to go, if you dont have one either distilled water is the next best way to top evaporated tank water. RO water from places for drinking water would be my last choice but the cheapest, but RO doesn't take out as much impurities as RO/DI water

 

[leptang]

My best guess of the tank is 3 to 6 months old from the look of the rocks. But i might be wrong.

 

[Reefing Madness]

Readings in the tank should be as follows: Also, what lighting do you have, and what kind of flow in the tank? How old is it?
[TABLE="align: center"]
[TR]
[TD="colspan: 3"]

Table 1. Parameters critical to control in reef aquaria.​

[/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Parameter:[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Reef Aquaria Recommendation:[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Typical Surface Ocean Value:[SIZE=-1]¹[/SIZE][/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Calcium[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]380-450 ppm[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]420 ppm[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Alkalinity[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]2.5-4 meq/L
7-11 dKH
125-200 ppm CaCO[SIZE=-2]3[/SIZE] equivalents[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]2.5 meq/L
7 dKH
125 ppm CaCO[SIZE=-2]3[/SIZE] equivalents[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Salinity[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]35 ppt
sg = 1.026[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]34-36 ppt
sg = 1.025-1.027[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Temperature[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]76-83° F[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Variable²[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]pH[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]7.8-8.5 OK
8.1-8.3 is better[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]8.0-8.3 (can be lower or higher in lagoons) [/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Magnesium[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]1250-1350 ppm[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]1280 ppm[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Phosphate[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]< 0.03 ppm[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]0.005 ppm[/SIZE][/FONT][/TD]
[/TR]
[TR]
[TD="width: 20%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Ammonia[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]<0.1 ppm[/SIZE][/FONT][/TD]
[TD="width: 40%"][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Variable (typically <0.1 ppm)[/SIZE][/FONT][/TD]
[/TR]
[/TABLE]


Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

 

[Randy Holmes-Farley Verified Community Expert]

My corals looked unhappy so I had my water tested by my lfs. Full battery of tests. Everything tested within normal limits. My alk was 11 or12, which i'm told is the high side of normal. I don't dose anything at all, just water changes using lfs water. He tested their water and their alk was at 9. What would cause it rise? How do I make my corals happy again? Thanks!

Unless, as mentioned, you are topping off for evaporation with tap water, the alkalintiy is coming from your salt mix. Many start at the level you have.

IMO, the alkalinity you have is not a problem in that sort of tank, just don't add any. No pH buffers, or frankly, anything.

There is no supplementation of any type needed if the salt mix is supplying all the alkalinity the tank needs, because it is also supplying everything else the tank needs.

As soon as coralline starts to grow more, or you get more hard corals that grow rapidly, the alkalinity will decline and you will begin to need to supplement.

 

[melypr1985]

How old is your tank?

Also what test kits are you using? And what's your cal and mag at?


And what lights your running?

I had my LFS (very trusted in my area) test my water. I don't have all the kits needed at home and they do it for free . I didn't write down the results of every test. I just know they were ALL within normal ranges. We had decided that the alk was on the high side of normal. My tank was started Aug. 1st.

 

[melypr1985]

Tap water.... dont use it for topping salinity. RO/DI system is the way to go, if you dont have one either distilled water is the next best way to top evaporated tank water. RO water from places for drinking water would be my last choice but the cheapest, but RO doesn't take out as much impurities as RO/DI water

I don't use tap water for anything. I go through the trouble to buy my top-off RO/DI and my salt water from the same LFS that tested my water. He tested his own saltwater as well, and his alk was at 9. mine is 11. Water is all I'm adding to the tank. We are both confused how my alk would rise when the water I'm doing water changes with has a lower alk.

 

[melypr1985]

My best guess of the tank is 3 to 6 months old from the look of the rocks. But i might be wrong.

Nope, you are right! good eye!

 

[melypr1985]

The light is a Fluval LED fixture. Not happy with it for what that's worth. Changing to T5's soon. I have one powerhead that does a great job by itself. (I had two but the sand was getting blown around so I ditched it).

 

[melypr1985]

Unless, as mentioned, you are topping off for evaporation with tap water, the alkalintiy is coming from your salt mix. Many start at the level you have.

IMO, the alkalinity you have is not a problem in that sort of tank, just don't add any. No pH buffers, or frankly, anything.

There is no supplementation of any type needed if the salt mix is supplying all the alkalinity the tank needs, because it is also supplying everything else the tank needs.

As soon as coralline starts to grow more, or you get more hard corals that grow rapidly, the alkalinity will decline and you will begin to need to supplement.

Don't worry, I'm not going to add anything. I think I will slow down on water changes for a bit too. Is it possible that my inhabitants aren't using up the alk before I change the water, so it just adds to what is already in the water? kinda like topping off with saltwater makes the salinity rise real fast? I'm still trying to work this chemistry stuff out in my head. please use small words! lol

 

[Randy Holmes-Farley Verified Community Expert]

Don't worry, I'm not going to add anything. I think I will slow down on water changes for a bit too. Is it possible that my inhabitants aren't using up the alk before I change the water, so it just adds to what is already in the water? kinda like topping off with saltwater makes the salinity rise real fast? I'm still trying to work this chemistry stuff out in my head. please use small words! lol

OK.

Water changes won't ever boost the alkalinity higher than the salt mix you are using, but it can keep it at that same level if there is no demand in the tank using any of it.