Canreef Aquatics Bulletin Board  

Go Back   Canreef Aquatics Bulletin Board > General > FOWLR

Reply
 
Thread Tools Display Modes
  #1  
Old 05-08-2009, 06:17 AM
jassz jassz is offline
Member
 
Join Date: May 2009
Location: Pitt Meadows
Posts: 80
jassz is on a distinguished road
Default Do I need to adjust my Specific Gravity?

Hi all, newbie here.

I just bought/moved an existing FOWLR tank last weekend. The previous owner apparently kept the SG at 1.024. We moved 100+ gallons of exisiting water (it's 135g with sump), and the new water was also tested at the time we added it (I'm not exactly sure what it was, the prev. owner checked it). So I'm quite baffled as to why now, not even a week later, the SG could drop to 1.019. I did change out about 15 gallons a couple of days ago (the nirtrate was climbing), and the SG of that change water was about 1.019, but I figured that 15 gallon wouldn't drop the overall SG. It doesn't make sense it could have dropped, so I'm a little suspicious of the hydrometer.

But if my SG really IS 1.019 (the readings are consistant), is it harmful to the fish or rocks to be at this level? Most fish seem fine, a couple seem lethargic but I don't know what they are normally like. What advantage would there be in bringing it up? How do I bring it up? I mean, I know you add salt, but how on earth do you gauge how much? From what I've read bringing it up too fast could be problematic.

Thanks for your help!
Reply With Quote
  #2  
Old 05-08-2009, 06:21 AM
mark's Avatar
mark mark is offline
Member
 
Join Date: Nov 2002
Location: Edmonton AB
Posts: 4,212
mark is on a distinguished road
Default

check your hydrometer, they do go bad and this article on bogus info
__________________
my tank
Reply With Quote
  #3  
Old 05-08-2009, 06:22 AM
belzebuth belzebuth is offline
Member
 
Join Date: Jan 2009
Location: Mission, BC
Posts: 207
belzebuth is on a distinguished road
Default Sg

I would bring it up to 1.022.
__________________
Andy
Reply With Quote
  #4  
Old 05-08-2009, 07:00 AM
Myka's Avatar
Myka Myka is offline
Moderator
 
Join Date: Mar 2004
Location: Saskatoon, SK.
Posts: 11,268
Myka will become famous soon enough
Default

1.022 to 1.026 is normal for FO and FOWLR tanks albeit there is no good reason to have it any lower than 1.025, where reefs should be 1.025 to 1.026.

Best bet it to either buy a refractometer $50-60 and periodically recalibrate your hydrometer (I've seen them off by as much as 0.008), or take a water sample to your LFS and get them to test with a refractometer so you can figure out how much yours is off by. I have two hydrometers (one is SeaTest and one is Coralife...I think); one is under by 0.002 and the other is over by 0.002.

For a really rough guestimate...about 2 tbsps will raise the sg by about 0.006 or 7 ish in 5 gallons. This is just my guestimate from mixing salt up in my buckets.
__________________
~ Mindy

SPS fanatic.

Reply With Quote
  #5  
Old 05-08-2009, 07:21 AM
Johnny Reefer's Avatar
Johnny Reefer Johnny Reefer is offline
Member
 
Join Date: May 2005
Location: Victoria, B.C.
Posts: 1,192
Johnny Reefer is on a distinguished road
Send a message via MSN to Johnny Reefer
Default

Quote:
Originally Posted by Myka View Post
...
For a really rough guestimate...about 2 tbsps will raise the sg by about 0.006 or 7 ish in 5 gallons. This is just my guestimate from mixing salt up in my buckets.
Unless I'm reading this wrong, I would think you'd need 5x that much (10 tbsps) to raise 5g by 0.006. According to Instant Ocean directions 2 1/2 cups will raise 5g to ~ 1.024.
1.024 - 1.000 = 0.024
0.024/4 = 0.006
2 1/2 cups = 40 tbsps
40/4 = 10
Therefore, would it not take 10 tbsps of salt to raise 5g of FW (1.000) to an SG of 1.006?
__________________
Mark.
Reply With Quote
  #6  
Old 05-08-2009, 02:30 PM
jassz jassz is offline
Member
 
Join Date: May 2009
Location: Pitt Meadows
Posts: 80
jassz is on a distinguished road
Default

Thank you for you replies. We use refractometers where I work, and check the zero (I think what you call calibrating) daily, as well as run two known controls. So I know they are accurate. I will take a sample in and check it.

So, if the SG is low, how might this affect the fish? The Stars and Stripes puffer seems very lethargic, and he was actually puffed this morning when I went down there. The dog might have scared him. He ate some food off a stick the second day or so, but I haven't seen him eat since. I also haven't seen the lion fish eat since the second day or so. Everyone else (2 triggers, another puffer and a wolf eel) are eating like pigs. I tested the water yesterday, and it was neg for ammonia, nitrate and nitrite, and the pH was 7.8 (which is what it has been since I got the tank). Is that a little low?

Thanks again.
Reply With Quote
  #7  
Old 05-08-2009, 08:13 PM
Myka's Avatar
Myka Myka is offline
Moderator
 
Join Date: Mar 2004
Location: Saskatoon, SK.
Posts: 11,268
Myka will become famous soon enough
Default

Quote:
Originally Posted by Johnny Reefer View Post
Unless I'm reading this wrong, I would think you'd need 5x that much (10 tbsps) to raise 5g by 0.006. According to Instant Ocean directions 2 1/2 cups will raise 5g to ~ 1.024.
1.024 - 1.000 = 0.024
0.024/4 = 0.006
2 1/2 cups = 40 tbsps
40/4 = 10
Therefore, would it not take 10 tbsps of salt to raise 5g of FW (1.000) to an SG of 1.006?
Well I did say it was a really rough guestimate, but it takes about 3 1/4 cups to get the sg to 1.026. I know that for sure because I put 3 cups and a bit in, and then I add a little more to adjust it.
__________________
~ Mindy

SPS fanatic.

Reply With Quote
  #8  
Old 05-08-2009, 08:27 PM
GreenSpottedPuffer's Avatar
GreenSpottedPuffer GreenSpottedPuffer is offline
Member
 
Join Date: Jan 2007
Location: Vancouver
Posts: 2,337
GreenSpottedPuffer is an unknown quantity at this point
Default

Quote:
Originally Posted by Myka View Post
1.022 to 1.026 is normal for FO and FOWLR tanks albeit there is no good reason to have it any lower than 1.025, where reefs should be 1.025 to 1.026.
Higher oxygen saturation in the water and ionic regulation of salt from the fish should be easier at a lower salinity. Nothing wrong with 1.019, I know a few FOWLR tanks running for many years at 1.018.

As for the Stars and Stripes, it shouldn't be the salinity bothering him. They often spend their juvenile lives in Brackish water estuaries. He might just be a lazy puffer as so many are.
Reply With Quote
  #9  
Old 05-09-2009, 06:55 AM
Myka's Avatar
Myka Myka is offline
Moderator
 
Join Date: Mar 2004
Location: Saskatoon, SK.
Posts: 11,268
Myka will become famous soon enough
Default

Quote:
Originally Posted by GreenSpottedPuffer View Post
Higher oxygen saturation in the water and ionic regulation of salt from the fish should be easier at a lower salinity. Nothing wrong with 1.019, I know a few FOWLR tanks running for many years at 1.018.
As much as I'm aware of this I've personally seen no benefit, and I don't see any rationale to keeping the salinity so far away from NSW.
__________________
~ Mindy

SPS fanatic.

Reply With Quote
  #10  
Old 05-10-2009, 06:06 AM
jassz jassz is offline
Member
 
Join Date: May 2009
Location: Pitt Meadows
Posts: 80
jassz is on a distinguished road
Default

So, I tested with the refractometer, and the reading was 1.016. So the hydrometer is inaccurate, but not in the direction I had hoped! I did add some salt today and will add more. I did'n't want to bring it up too fast.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT. The time now is 08:28 AM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.