Salinity control

[chemmom]

I know that I am to use RO water when topping off, but if I notice that my salinity is a little lower than I'd like can I use some saltwater for top off or just wait until the next water change?

 

Right now my salinity is 1.022, but I'd like it at .023-.024. I'm concerned about my fishes. Is this a negligible difference? Not too detrimental too them? Like, what would be a big swing that I should be concerned about their well being?

 

Thanks again!

[Physh1]

Fish are fine with .019 to .023 w/o issues. A 22 to 23 difference is negligible. I'd just wait till a water change to adjust it to 23 if that is where you want it. There is no harm at all at 22.

 

Cameron

[zizmans]

Do you have fish only? I'm also curious as to your tank size and specimens.

 

By the way 1.025 although optimal for inverts is not so for a F/O tank. Studies have shown Fish do much better at lower salinity say around .021.

[AnthonyNguyen]

hum, that kinna weird, i kept my b/w 1.023 and 1.025, and fish seem to be ok.

[chemmom]

I have a 7 gallon minibow with 2 percs. About 10 lbs of live rock.

 

It is fish only for awhile. I need to do more research before I get into corals.

 

By the way, thanks to those who answered me about feeding my fish. I researched and tried a syringe to feed them with, a suggestion I read, and it worked great! I could put just enough in, watched what they ate and then added more a little at a time. Much more controlled than just dumping in flakes (which is what I do with my freshwater - and I have the algae to prove it!)

 

I just used one of those 5mL plastic syringes I get free from my pediatrician when my kids are sick. Have plenty of those lying around the house ...

 

Thanks

[Ike]

Well, natural seawater is @ 1.026 so I would try to raise it to that. In fact, much of what I've been reading lately leans towards a higher specific gravity is less stressful than a low one.

 

That being said, it's OK to do it eaither way. Top-off will be a more gentle methd though. Just be sure to test while you're doing it. Once you reach yor desired level just try to maintain a consistent level from then on.

[Tempest]

Actually, for fish, a slightly lower than normal SG is less stressful. Fish have to get rid of the salt through their gills. However, I've read that they need salt to help clean their kidneys though there seems to be some disaggreement over this (checkout Reefcentral.com). Inverts and coral like the salt closer to normal sea water SG 1.025-1.026.

[Dingo]

Fish are not stressed by being kept in the conditions that they have spent millions of years adapting to. Full strength sea water is what they are born to be in, and changing that is what causes stress.

 

Keeping them in a lower salinity than they are used to stresses their kidneys because it changes the osmotic balance between the inner and outer environments of the organism, resulting in early kidney failure.

[onthefly]

The salinity of sea water varies based on location..Red sea (hig evap=1.027)...Pacific (much less evap and larger body of water=1.024)....tide pools in the afternoon (really high SG!).

 

I've had my percs, flamehawk, chromis, etc at 1.018 for almost 5 years. Fish can acclimate to a WIDE range of salinities.....take migratory species for example or the daily changes in salinity in mangroove or tidal zones. The key point is "acclimation"!

 

Having marine species acclimated at a lower SG is easier on their systems do the lower osmotic pressure (it's easier for them to excrete the salt). Another positve note to a lower SG is the decrease in parasite activity in lower SG.

 

All this being said, I probably wouldn't buy a species of fish indigenous to the Red Sea (or a species easily stressed) and try to place them in a 1.018 tank....too much away from their normal environment. Like everyone else, I lose fish from time to time, but this system has worked will for me.

[maroonclown]

Some of the hardiest zoos can also be acclimated to a higher salinty-brakish water; somewhere between 1.014-1.019. Of course, its just some zoos. Some LPS corals can tolerate wide sg swings from 1.026 (natural seawater) to something like 1.035! These are the ones unfortunate enough to be in the tidepools. Some can survive exposed to air; they're often exposed at low tide in the wild. I wouldn't recomend doing this, but it would be cool if someone had the money, time, and space to set-up a tidepool that did just that. I like to keep my tanks at natural seawater, and I keep my QT at about 1.016. A little low, but I have lost a new fish yet.

[nalbar]

yes chem you can use salt water for top off. depending on your tank you may find you use SW for top off more frequently than FW. this is because of salt creep. in fact, that is the case for me, on top off it is 2 SW's to 1 FW's.

 

nalbar