I have a decent amount of evaporation and everytime i go to change my water my salinity is always higher then it was and it makes sense that less water due to evaporation means more salinity but is this ok for my tank do i need to change water more often or am I all good. This last time my salinity went from 1.025 to about 1.029 the hydrometer couldn't read it correctly anymore.
Does salinity rise over time?
- Thread starter THEACOX88
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spspirate
Tidepool Explorer
You need to invest in a good refractometer. Some times a hydrometer is not all that accurate. You may want to set up a auto-top-off unit to give you a consistent water level and inturn a consistent specific gravity. You may loose salt over time through skimming but for the most part it should stay somewhat the same. What size system are you running?
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jasonp87
Well-Known Member
It shouldn't be going up, unless you are topping off with salt mix instead of RO/DI. I tend to see mine go down slightly overtime due to loss of salt from salt creep and removing small amounts of water for tests and frags that gets replaced with RO/DI from my ATO. Mine is always very slight and nothing a small water change can't correct.
In my experience, salinity tends to drop, not rise. I've always attributed this to creep and removal of salt water by the protein skimmer, testing, wet hands, and so on. My towel tends to be moist then dry crusty - salty. I'm curious now if this is everyone else's experience. Tagging along.
akma
Well-Known Member
So between water changes you don't add ro/di water to make up for the water lost through evaporation? If so you can just top off manually for now until you setup the ATO. Don't top off with mixed saltwater.
birdmandan
Active Member
++1 on the refractometer. I never thought to clean my hydrometer and it led to a tank crash awhile back. I was curious as to why I was adding 5 cups of salt to a 5 gallon bucket instead of 2.5... Common sense goes a long way in this hobby but its still smart to make sure your equipment is clean and accurate. Your salinity will rise as water evaporates. Add fresh water to counter that. However, as others have stated, I too have found that salinity drops over a longer period of time due to salt creep and such.
kschweer
Moderator
Top off water should be just rodi water. This is because salt does not evaporate only water. Topping off with saltwater would explain the rise in salinity. Also if you're checking you're salinity when you haven't topped off it would be higher as well, again because only water is evaporating not salt. As stated above an auto top off is a great investment.
kschweer
Moderator
There's a lot of different ones out there. I personally like the avast marine ATO. I use them on both of my tanks. Very easy to use and I have had no problems with them.
http://www.avastmarine.com/ssc/do/product/rigging/Top-off-Kit
All you need is a small powerhead and a container of some sort to hold the rodi water. I use a 5g bucket on my frag system and an acrylic top off container for my display.
gmastr85
Active Member
I agree with everything said here so far!
Get a Refractometer.. Dump the hydrometer! They are inaccurate and inconsistent.
For the long term health of your tank, invest in an ATO. It will stabilize your tank. You won't have salinity swings like you are having now! You will end up crashing your tank.
When water evaporates the salt stays behind, which causes your salinity to go up. If you are topping off with saltwater instead freshwater, you will just keep raising the salinity. The salt doesn't go anywhere. Thats probably why its so high.
Remember:
Top Off with RO/DI Freshwater
Water Changes with RO/DI Saltwater
Get a Refractometer.. Dump the hydrometer! They are inaccurate and inconsistent.
For the long term health of your tank, invest in an ATO. It will stabilize your tank. You won't have salinity swings like you are having now! You will end up crashing your tank.
When water evaporates the salt stays behind, which causes your salinity to go up. If you are topping off with saltwater instead freshwater, you will just keep raising the salinity. The salt doesn't go anywhere. Thats probably why its so high.
Remember:
Top Off with RO/DI Freshwater
Water Changes with RO/DI Saltwater
Another option for an ATO is a 5 gallon bucket with a rigid 1/4 tube through a hole in the bottom. Then put it above the top of your sump and use a simple mechanical float to control the water flow. I would recommend putting it in a place away from any fauna or flora that might block the hole and cleaning it regularly. Its much cheaper to make that buying a commercial ATO unit but you sacrifice the redundancy most of those units have. If you need more details PM me, I was short cuz I'm using my phone atm.
I am having the an issue with salinity rising over time. I have a Tunze ATO so it is not evaporation. I dose using the BRS/Tropic Marin Balling method. I think the my dosing is raising my salinity.
I don't mean to hi-jack your thread but I have a similar issue.
I don't mean to hi-jack your thread but I have a similar issue.
