Alkalinity and pH issue... looking for advice.

[TJ Merrells]

I have a 5 gallon Fluval spec v that's been running for over a year.

The past couple months my corals have been dying and very unhappy the ones that are left.

Went out and bought all new red sea test kits. 2 weeks after a water change my parameters are as follows:

Salinity- 1.025 (Reef crystals)
Temp- 78
Ammonia- 0
Nitrite- 0
Nitrate- 0
Ph- 8.0
Dkh- 6.5-7
Phos- 0
Calcium- 420
Magnesium- 1320

I have 5 sexy shrimp, a pom pom and just a couple corals frags, ornate setosa, hammer, Xenia, acan, zoas.

In my filter chamber I run filter floss, poly filter, and Marine pure spheres and I use an ato for top ups.

My first concern was lack of nutrients so I removed the poly filter and a day later after a water change I have a small just detectable amount of phosphates and 5 nitrates.

My biggest concern is my alkalinity being so low. As when I mix saltwater (Reef crystals) and test the dkh is 11. Do a water change and the dkh is still 7. Not sure how this is possible as I don't have much live stock.

I'm on well water so I'm suspecting I'm getting CO2 in my water. Bubbled my new saltwater for several hours before a water change and my top up water so dissapate the CO2. Still after a water change my SW was 11 and tank was 7.
As I was suspecting the CO2 in my tank was driving down my ALK.

My other concern is my ph. I'm fine with 8.0 in my tank but when I test my source water and my new saltwater before a change its yellow... Which with a red sea kits is so low it doesn't even register but still my tank is at 8.0 so I'm not sure how that makes sense.


If anyone could provide me with some insight that would be appreciated. Thx

 

[Richard Newman]

Hi @TJ Merrells ,
I am sure you will get lots of great advice here. Based on my experience, from your level, yes dKH is a little low, but standard sea water has a dKH of 7. I believe your biggest issue is low nutrients. You mentioned that you were able to raise them to detectable phosphate and 5 nitrates. That should get your remaining corals looking better in a few days. And it will take a couple of days.

I am sure others with more experience will ask other questions to hopefully give you a more concrete answer.

Hang in!

 

[TJ Merrells]

Hi @TJ Merrells ,
I am sure you will get lots of great advice here. Based on my experience, from your level, yes dKH is a little low, but standard sea water has a dKH of 7. I believe your biggest issue is low nutrients. You mentioned that you were able to raise them to detectable phosphate and 5 nitrates. That should get your remaining corals looking better in a few days. And it will take a couple of days.

I am sure others with more experience will ask other questions to hopefully give you a more concrete answer.

Hang in!

Yes I think taking out the poly filter and getting assume detected nutrients will help.

I'm just baffled as to why my new SW has an alk of 11 but tank stays at 7 and also why my ph in newly mixed saltwater is so low it doesn't even tank of the kids color charts

 

[Richard Newman]

It could be issues with the test kits. Can you take some samples to a LFS?

 

[TJ Merrells]

It's not the test kit. I'm using brand new red sea and salifert for calcium and magnesium. I know they're good because the LFS that I bought the red sea kits off of used the kit for a couple tests before I picked it up (know the owner personally so he borrowed a couple tests from it)

 

[Richard Newman]

Hmm. Not sure. Definitely odd. How much water are you changing out at a time?

 

[TJ Merrells]

Hmm. Not sure. Definitely odd. How much water are you changing out at a time?

I work away from home 2 weeks at work 1 week home. So I was doing a 50 percent change the day I get home and 50 percent the day I leave as the general rule of thumb with picos is 50-100 percent weekly. I'm going to cut those down to 20 percent. I also dose with microbacter7 on water change day

 

[JimWelsh]

As I was suspecting the CO2 in my tank was driving down my ALK.

Excess CO2 will lower pH, but will not affect alkalinity. Driving off excess CO2 will raise pH, but will not affect alkalinity.

 

[TJ Merrells]

Excess CO2 will lower pH, but will not affect alkalinity. Driving off excess CO2 will raise pH, but will not affect alkalinity.

Oh ok. I had read somewhere that it can also affect ALK. Any advice helps. Thank you

 

[Randy Holmes-Farley]

Alkalinity of 6.5-7 dKH is not a cause of corals failure to survive. That about matches the ocean.

 

[TJ Merrells]

Alkalinity of 6.5-7 dKH is not a cause of corals failure to survive. That about matches the ocean.

Yes but I'm using Reef crystals that has an alk of 11. So after water changes it must be swinging from 11-7

 

[Randy Holmes-Farley]

Yes but I'm using Reef crystals that has an alk of 11. So after water changes it must be swinging from 11-7

You do 100% changes?

A 10% change (with alk of 11 dKH on a tank at 7 dKH) only boosts alk to 7.4 dKH.

 

[TJ Merrells]

You do 100% changes?

A 10% change (with alk of 11 dKH on a tank at 7 dKH) only boosts alk to 7.4 dKH.

I was doing 50 percent water change twice the week I was home. Now I plan on doing 10 percent changes.

I made a visit to a LFS owner that I trust to get some advice. His thought was seeing I'm on well water I might have CO2 built up in my tank. I started running a bubbler in the new mixed SW and ato water outdoors. Also running a bubbler in my back filter chamber. Within an hour my corals began opening up more. After 24 hours my ALK jumped up to 9 and been holding steady there for several days.
I haven't seen my corals so open and puffed up in months.

I'm also running a 1/3 of the poly filter that I was and have removed the filter floss. I will only be running it before and after water changes. I now have between 2-5 nitrates.


I fly back to work tomorrow for 2 weeks so we will see how it holds up but as of right now it seems as though the issue was CO2 being built up in my tank and needed a bubbler to bring in more oxygen and dissipate the excess CO2

 

[Randy Holmes-Farley]

Aeration does not (it cannot) change alkalinity. I’m not sure what you are measuring. It can change pH.

 

[TJ Merrells]

Aeration does not (it cannot) change alkalinity. I’m not sure what you are measuring. It can change pH.

Yes alot of this confuses me also. I've been doing alot of reading but it seems to be helping none the less

 

[Randy Holmes-Farley]

Yes alot of this confuses me also. I've been doing alot of reading but it seems to be helping none the less

No. Aeration cannot raise alkalinity. It is simply impossible. It’s like saying I drove the car for an hour and found more gas in it after driving it. Either the measurement is in error, or gas (alkalinity) was added some other way.

 

[TJ Merrells]

I understand that. From what I've read high CO2 can throw off alk tests. And my high CO2 and most likely low o2 was affecting the health of my tank

 

[Randy Holmes-Farley]

I understand that. From what I've read high CO2 can throw off alk tests. And my high CO2 and most likely low o2 was affecting the health of my tank

elevated CO2 will not significantly impact an alkalinity titration.

 

[TJ Merrells]

elevated CO2 will not significantly impact an alkalinity titration.

Then I have no idea what's going on

 

[Randy Holmes-Farley]

The concern is corals not thriving?

You are using well water? Do you purify it? Have you had it tested for heavy metals?