My new sps become thin

[black_art]

Hey guys,
I got some Acros from one of my friend about one month ago but now they become thin and I think they got STN while my old sps are ok. My tank parameters are:
Nitrate:0
Phosphate:0
Ca:440
Mg:1440
Alk:7
Ph:8.1-8.2
Light: MH 14000K + 2 Geisman actinic + one 17000k Geisman+ 420nm Geisman(all Geisman are 54w)
all tests are Salifert.
Any idea why those become sick???
Thanks

 

[Tahoe61]

Thanks for providing water chemistry.

Really need an image as to your description of thin. Chemistry looks good.

Do you mean they are loosing tissue? Have you checked for pest? While an alk of 7 is usually ok in an ultra low nutrient system I would double check that result. If that value is dropping into the 6 range that is most likely the issue.

Welcome to Reef2Reef.

 

[black_art]

Thanks for providing water chemistry.

Really need an image as to your description of thin. Chemistry looks good.

Do you mean they are loosing tissue? Have you checked for pest? While an alk of 7 is usually ok in an ultra low nutrient system I would double check that result. If that value is dropping into the 6 range that is most likely the issue.

Welcome to Reef2Reef.

Thank you for your replay.

 

[evolved]

What's your flow situation like?

 

[Sabellafella]

Its flow related issue if you bought a full colony

 

[evolved]

And also with the algae growth I see on the skeleton and rockwork, you may have more nutrients than you think.

 

[black_art]

What's your flow situation like?

Its flow related issue if you bought a full colony

I have jebao rw-8 and one Seio 1500 and my tank is 130 cm * 50 cm. I bought it as a full colony. what should I do? change its location or increase its waterflow?

 

[black_art]

And also with the algae growth I see on the skeleton and rockwork, you may have more nutrients than you think.

Thank you. I have GFO and I use sugar but I have not changed my GFO material since 6 months ago because Phosphate test showed me 0. Do you think changing it is enough or I should do something more.

The little wave maker in behind is not working.

 

[evolved]

Phosphate test showed me 0

But how are you testing it? With what brand of kit? It's likely below it's lower limit of detection.

Flow looks to be an issue to me with the pic; increase flow in that spot or move it.

 

[robert]

"I use sugar"

See my post 56 in this thread:

https://www.reef2reef.com/threads/why-is-my-sps-peeling-and-turning-white.211149/page-3

 

[black_art]

But how are you testing it? With what brand of kit? It's likely below it's lower limit of detection.

Flow looks to be an issue to me with the pic; increase flow in that spot or move it.

I use Salifert test kit. here my new test results:
No3:2.5
Po4:0
Kh:6.4
Ph:8.1
Ca:380
Mg:1410
Temp:25C

 

[black_art]

"I use sugar"

See my post 56 in this thread:

https://www.reef2reef.com/threads/why-is-my-sps-peeling-and-turning-white.211149/page-3

Thank you. What about BioPlete do you think it may cause such problems too?

 

[ReefMadScientist]

I use Salifert test kit. here my new test results:
No3:2.5
Po4:0
Kh:6.4
Ph:8.1
Ca:380
Mg:1410
Temp:25C

Kh is low along with your Ca.

 

[black_art]

Kh is low along with your Ca.

Do you have any idea why Kh and Ca are decreased while I change about 7% of tank's water every week?

 

[ReefMadScientist]

Do you have any idea why Kh and Ca are decreased while I change about 7% of tank's water every week?

I believe the low kH is problematic to RTN. I had that issue before when my kH dropped below 7.

Your parameters seem really good before your water change. IMO, no need to change your water when it is already clean

You may want to look into 2-part dosing. I do this to maintain my kH and Ca. It is simple and efficient. But definitely bump up your kH and Ca SLOWLY.

 

[ReefMadScientist]

Oh and usually a sign of your kH being low is when your SPS start RTN'ing from the bottom-up. Of course this is a horrible sign to go by but gives you an idea of whats going on. I test my water periodically.

 

[robert]

Thank you. What about BioPlete do you think it may cause such problems too?

First the sugar, here's the data. You decide. Note while everything is labled mM they meant microM and issued a correction.

Biopellets would be a better choice, however it will raise DOC unless skimmed very effectively.
What should DOC levels be? Again data speaks for itself:

I'm not a fan of carbon based solutions - I even have reservations with respect to macro-algae unless very well cultured.

My solution is shown here:

https://www.reef2reef.com/threads/diy-sulphur-denitrator.211365/

 

[Randy Holmes-Farley Verified Community Expert]

I've never been a fan of sugar dosing, but that said, do you have a link to that paper so I can see what they actually did?

For example, was carbon maintained at that concentration for 30 days, or a single dose?

 

[black_art]

First the sugar, here's the data. You decide. Note while everything is labled mM they meant microM and issued a correction.

Biopellets would be a better choice, however it will raise DOC unless skimmed very effectively.
What should DOC levels be? Again data speaks for itself:

I'm not a fan of carbon based solutions - I even have reservations with respect to macro-algae unless very well cultured.

My solution is shown here:

https://www.reef2reef.com/threads/diy-sulphur-denitrator.211365/

Thank you so much. I have always seen amazing tank which made based Zeovit method. Do you have any Idea about this method(I think carbon is used in it too)?

 

[black_art]

Oh and usually a sign of your kH being low is when your SPS start RTN'ing from the bottom-up. Of course this is a horrible sign to go by but gives you an idea of whats going on. I test my water periodically.

Would you please let me know whether decreasing Ca by 60, Mg by 50 and Kh by 2 or 3 in every week is normal for my tank regarding changing 7% percent of water. I use red sea coral pro salt.