Fast salinity drop - help

[diablo243]

Ok so checking parameters ever other day from sump for DT. Checking temp, salinity, PH, Ammonia, Nitrite, Nitrate. This is the 4th check of the tank and between the last check (which was really 3 days) 15th and today salinity has dropped from 35ppm to 30ppm. Check the refractometer calibration and that's good so reading seems correct. Here is what has happened in this days that were changes:

New heater added and temp raised to 81, last night reduced back to 79

ATO added, I have a line on the sump and it has been spot on. Using a float switch and aqualifter, but the level line is spot on so don't think it's over filling (plus being down in sump room I see it come on and off, so know it's working and not just on)

So what does everyone think? No visible salt creep anywhere as buildup. And how do I adjust salinity on the fly now?

Thanks all!

 

[diablo243]

As a note if it was not clear tank is still cycling and has not fish or coral.

 

[blacktippr]

do you have a skimmer?

 

[diablo243]

Yep but not running yet

 

[jaws789832]

As a note if it was not clear tank is still cycling and has not fish or coral.

 

[billw]

How cold was your water when you measured 35 ppm?

 

[diablo243]

35 was read at a minimum of 79 and also at the first day of 81

 

[billw]

35 was read at a minimum of 79 and also at the first day of 81

It was a longshot . You can adjust it back by simply adding more salt water and let evaporation bring it back up or if you're in a hurry, mix up some stronger (40 ppm?) saltwater and do a water change until it's back.

 

[diablo243]

Ok thanks I'll start a batch mixing today

 

[jaws789832]

I believe temp affects salinity although I dont think it would be that drastic. In my tank for every .5 degree temp change my saliny changes .3 ppt. At 78 degrees I am 35 ppt, at 78.5 I am 35.3, and at 77.5 I am 34.7 ppt. Thats using a apex salinity probe and occaisionaly double checking wity the milwalkie ph checker. You can probably just raise it up to what you want with no ill affects. If you had livestock, just add saltwater to your ato until it gets to where you want, then switch back to fresh

 

[billw]

I believe temp affects salinity although I dont think it would be that drastic. In my tank for every .5 degree temp change my saliny changes .3 ppt. At 78 degrees I am 35 ppt, at 78.5 I am 35.3, and at 77.5 I am 34.7 ppt. Thats using a apex salinity probe and occaisionaly double checking wity the milwalkie ph checker. You can probably just raise it up to what you want with no ill affects. If you had livestock, just add saltwater to your ato until it gets to where you want, then switch back to fresh

Yea, it would have to have been a 50 degree to 80 degree swing, hence the longshot

 

[kgstei]

If this is your first test since adding the ATO I would be suspicious that that might be the cause maybe in the process of hooking up your ATO you added too much fresh water and dropped it right then not picking up on it until you tested today

 

[diablo243]

I mean I am suspicious of that as well being it coincides with the timing but I've been watching it and it's not adding much water ever. Keeps the level spot on, and if anything I would have suspected the levels to have risen as the line I used to mount the float switch ended up being higher then when the float switch actually activates. So the over all level has reduced since the ATO (not by much) but it is getting less ATO than when I was tipping it manually every day. Will get it balanced and watch it, and hope it was just a settling fluke.

 

[diablo243]

So to raise so I do a water change or stop the top off for a couple days and just top off with salt water till it balances? Keeping in mind tank is not stocked and still cycling?

 

[diablo243]

And if water change is best option should I do several smaller ones or one big one? 90ga DT 30ga sump 100lbs live rock and 1" sand bed so prob round 100 or so total ga

 

[kgstei]

I don't see any point in a water change you could pull water out of your tank add salt to that raising its salinity and add it back to your tank until you reach your desired salinity mix it well

 

[jaws789832]

Also is the tank going to be a reef tank? Reason I ask is most fish I get are in 30 ppt water. This is what I keep my QT at and slowly raise the Qt water via top off. If its a fowlr tank30 probably isnt that bad

 

[diablo243]

Will be reef

 

[Wesus]

You can add salt slowly to filter sock

 

[Reefrookie220]

Add saltwater to your ato resivor and let it balance out.