this might be a dumb question but idc...

jminick2

New member
So Ive been doing this awhile, I have always topped off with rodi water and I have always read on here topping off this saltwater is bad cause it will make your salinity rise. I have never really thought twice about it.

Today I want to bring the water level up another couple inches in my stock tank to put it closer to where I needs to be for my skimmer. Why is it ok to add 1.025 water to existing 1.025 water to do what I'm doing today, but its not ok to top off with matching SW. Isnt it kind of the same concept? Maybe my brain isn't working today but I just cant wrap my head around it.
 
I get you are just replacing evaporation with top off water but if you were just using 1.025 water wouldn't it just mix evenly rather than raise salinity?
 
Only water evaporates. So if evaporation removes 1 gallon of water, it leaves the salt from that gallon behind. This makes the water a little saltier, no longer the desired 1.025. If you then add salt water to replace that gallon, you don't offset the extra saltiness, thus increasing salinity. Adding RODI water will bring the salinity down to where it should be.

Adding a couple gallons to your existing water to raise the level should be done after you top off to your normal level. Then you wont see a raise in salinity then either.
 
Because when water evaporates, the minerals stay. So as your water evaporates and your water level goes down, your salinity goes up. If you are just trying to raise your water level, and are going to maintain that water level, the new saltwater matches the old saltwater to increase the level.
 
Your adding to an existing water level, rasing the water level, this is OK. If you were to add RO/DI to bring up your water level your salinity would decrease.

When topping off, its the water that evaporates leaving the salt behind(effectively raising your salinity), so you need to add back that fresh water to mix with the salt to bring the salinity back down to where it should be.

No question is dumb if you don't know the answer. :thumbsup:
 
I don't think it's a dumb question! Hopefully someone with more experience will chime in shortly. In the meantime, let me offer my (little) experience:

You don't want to add salt directly to the DT because it can burn your fishes' gills. Also, raising your salinity too quickly can shock your fish.

What I'd recommend doing is to add a bit of salt when you top off and doing this incrementally (maybe daily).

If you have 1.025 water in your tank and then you have 1.025 in your top-off, your raising the concentration of salinity. Right? Water will evaporate but the salinity will remain the same.
 
Man I feel dumb. I thought about everything except salinity rising during evaporation all makes sense again! Thanks fellas. mods delete this post before anyone else reads it!
 
Man I feel dumb. I thought about everything except salinity rising during evaporation all makes sense again! Thanks fellas. mods delete this post before anyone else reads it!


Everyone needs to feel they can ask questions, especially here! Because us as a community need to take care of our own and progress our hobby. I feel the more informed you and I are the better the community will be as a whole.

With that being said, there is also a lot of information in the stickes. Don't forget to check them out next time.

Again, never feel like you can't ask!
 
this might be a dumb question but idc...

Yea except the elitist that butcher you for questions like these On down the road.
 
I think what hung me up was the whole adding water to the stock tank you don't do that very often usually you are changing water or topping off. Then I started thinking well if I can do this why can't I top off with saltwater. The whole salinity rising during evaporation got away from me. To be honest I use to think of you topped off with SW your salinity would sky rocket in a couple days but in reality it would take a little longer.

None the less I appreciate the help. Thank you everyone.
 
Hey jminick2, I've been at this hobby about 11 or 12 years now and I'm still learning new stuff all the time. Some of it stuff I probably should already know! It's about asking the question and learning, not about how much you know!
 
Please, ask away and never feel dumb about it. I don't care if the question has been asked / answered a 1,000 times, if I can provide an answer I will. I hate it when folks on this forum give people a hard time for asking a question or point them to the stickies. Folks tend to forget they were new once and maybe the poster read the stickies and being new, didn't understand what he read.

As I mentioned, never worry about asking a question. There's good people on this board and the ones that give people crap should be ashamed of themselves.
 
yes, please don't delete.

this seems to be the topic of the day, as this is not the only thread on the subject.
i had not taken this into consideration. went and checked mine and it was 1.032+

quick run to store and getting this taken care of
 
The only dumb question is the one you do not ask. Based on the discussion here, a lot of folks learned something today.
Thanks for asking.
 
Yea except the elitist that butcher you for questions like these On down the road.

That's troubling to hear. Don't be afraid to report posts that make you feel this way. I used to go round and round with people when I thought they were out of line, and be reluctant to report posts cause in real life I tend to handle things myself rather than go snitchin. But I'm learning that it really is better to bring in a mod now and then. Like, rather than win an argument you can make the forum more helpful overall by sending things up the food chain.

Sometimes I can be kind of elitist too, but I hope I never butchered you :) a lot of those disagreements really are miscommunications. Where someone doesn't understand how they come off without all the visual cues we rely on in normal conversation to show that we are just teasing. But it's about people needing to learn to post without being jerks, not about people needing thicker skins. Nobody should be reluctant to ask even the dumbest questions. In fact, the dumb Q's make noobs like me feel smart for being able to help, that feels good like hitting the slow pitches in baseball :dance:
 
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