Low Alkalinity

[spamvicious]

Yep, that looks right.

I’ve ordered some tests for calcium and magnesium so I will see what they say.

 

[vetteguy53081]

Checked the salinity and it’s 1.25. I’m using a salifert test. I tested yesterday evening and it was 4.5 and tested just now (11:30am) and it’s 4.8. The two frags I have are gps and xenia.

Do a simple test. . . Is it your test kit, false reading , salinity ?
Take a water sample to a trusted LFS that does Not use API kits and see what readings they come up with to compare with yours

 

[spamvicious]

Do a simple test. . . Is it your test kit, false reading , salinity ?
Take a water sample to a trusted LFS that does Not use API kits and see what readings they come up with to compare with yours

The salinity is fine and the test kit is giving the same results each time. Both the Red Sea kit and the salifert tests are giving results between 4.5-5.0 so there is obviously an issue

 

[gbroadbridge]

The salinity is fine and the test kit is giving the same results each time. Both the Red Sea kit and the salifert tests are giving results between 4.5-5.0 so there is obviously an issue

Baking soda is the answer.

 

[vetteguy53081]

The salinity is fine and the test kit is giving the same results each time. Both the Red Sea kit and the salifert tests are giving results between 4.5-5.0 so there is obviously an issue

I has similar and added seachem alk and its holding at 8.8. While sodium bicarbonate will help, the number at times drop.

 

[gbroadbridge]

I has similar and added seachem alk and its holding at 8.8. While sodium bicarbonate will help, the number at times drop.

The OP needs to add alkalinity.

Sodium Bicarb (Baking Soda) is all that is needed.

Seachem Alk adds other chemicals that are not needed.

 

[reaper93]

First check salinity as that affects everything else.

Use a salifert ALK test kit.

If that is normal, go to the pantry and grab some baking soda and use that to increase Alk.

The calculator is here

Reef Chemistry Calculator

I've heard this said a bunch. How much of a salinity change would effect your levels?

 

[Garf]

I've heard this said a bunch. How much of a salinity change would effect your levels?

10% change of salinity would change everything by 10%.

 

[thatmanMIKEson]

What size is this tank? Are your 2 corals looking very upset? Do you have fish do they look very upset? If not just start doing weekly or bi weekly waterchanges with known values (test new saltwater) you could do a large waterchange first if its feasible something50-100%, the corals you have shouldn't mind, I would make salt water never buy it premixed that's the best way to insure it's the way you want it, and alk drops over time so fresh is the best.

 

[reaper93]

10% change of salinity would change everything by 10%.

So it's just a ratio and "making a difference" is just a matter of how much of a salinity change would be noticeable with the test kits we use right? Thanks for clearing it up

 

[thatmanMIKEson]

Sorry double post

 

[gbroadbridge]

10% change of salinity would change everything by 10%.

No.

Define a 10% change in salinity. Are you talking PSU? Or perhaps some metric that is variable?

 

[Garf]

No.

Define a 10% change in salinity. Are you talking PSU? Or perhaps some metric that is variable?

You can use whatever measurement you want. If you thin it out by adding 10% of the volume in extra RODI, everything within will be 10% diluted. Same the other way. Allow evaporation to concentrate the solution by losing 10% in volume and the contents will be more concentrated by 10%. I’m sure someone will give a theoretical reason why it can’t be exactly 10%, but nearly 10% is 10% in my book.

 

[vetteguy53081]

The OP needs to add alkalinity.

Sodium Bicarb (Baking Soda) is all that is needed.

Seachem Alk adds other chemicals that are not needed.

Baking soda stabilizes it and seachem has buffers in addition to alk which works and balabces with Calcium.
Bicarbonate has to be limited to 1dkh per day or will cause coral to go into shock or suffer tissue loss.
Also it was not seachem but red sea reef foundation B that I used.

 

[NanoCrazed]

You can use whatever measurement you want. If you thin it out by adding 10% of the volume in extra RODI, everything within will be 10% diluted. Same the other way. Allow evaporation to concentrate the solution by losing 10% in volume and the contents will be more concentrated by 10%. I’m sure someone will give a theoretical reason why it can’t be exactly 10%, but nearly 10% is 10% in my book.

It's not terribly linear like that, especially once that water is in a reef / tank system. You could have 1.025 and all different values of alk and CA, etc. There's a relationship of between alk and ca that's a bit more dynamic than simply dependent on salinity and dilution, with Mg helping to maintain that balance...

 

[Reef.]

Been running my tank for 10 weeks. Three weeks ago my alk was 5, I was advised that it was maybe the test kit I used as it seemed low. I changed the test kit and got a result of 6.8. I tested again today and it’s 4.5.

I have two small coral frags but otherwise just a few fish and cuc. I get both my ro water and pre mixed salt water from the local fish store which is well established and has a good reputation.
What should I do?.

First don’t assume your LFS because it has a good reputation and is established means they sell good salt water.

Also a new tank uses alk, even without corals so your alk could very well be 5dkh.

 

[Garf]

It's not terribly linear like that, especially once that water is in a reef / tank system. You could have 1.025 and all different values of alk and CA, etc. There's a relationship of between alk and ca that's a bit more dynamic than simply dependent on salinity and dilution, with Mg helping to maintain that balance...

I think you’re talking about precipitation, abiotic or otherwise. I’m talking dissolved solids.

 

[Garf]

It's not terribly linear like that, especially once that water is in a reef / tank system. You could have 1.025 and all different values of alk and CA, etc. There's a relationship of between alk and ca that's a bit more dynamic than simply dependent on salinity and dilution, with Mg helping to maintain that balance...

I’m bored so I tested my new saltwater then diluted it 50% and tested that, lol. 9.9, and 5 ish

 

[thatmanMIKEson]

I’m bored so I tested my new saltwater then diluted it 50% and tested that, lol. 9.9, and 5 ish

Colors are a bit different but not to much..

 

[thatmanMIKEson]

I’m bored so I tested my new saltwater then diluted it 50% and tested that, lol. 9.9, and 5 ish

That's probably the salinity difference tho right ?