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Salt measurement check

Posted: Sat May 09, 2020 2:00 am
by Neleono
I just bought some sea salt from one of the approved instant ocean products and I would like to be sure my measurements are correct. If one gallon of water calls for half a cup of salt how much salt would 2 cups require. I just want to be sure of my measurements before I give it to my crabs. Sorry for the bigger numbers, I accidentally ordered a 14 pound bag lol. Thanks for the help!

Re: Salt measurement check

Posted: Sat May 09, 2020 6:57 am
by Motörcrab
Be sure to check out our Care Sheets, Guides, and FAQ's.

This is covered in the, Care: Water - Fresh, Salt, & Why to Use a Dechlorinator area.


Re: Salt measurement check

Posted: Sat May 09, 2020 9:49 am
by Links
These measurements are spot on but I used to find myself adjusting the saltwater after checking with a calibrated refractometer. I calibrate it with calibration liquid I got at a pet store. It can be calibrated using distilled water but the calibration liquid is more accurate.

For some reason when I mix a gallon I use slightly less than 1/2 cup. Every time I used exactly 1/2 cup per gallon I’d get readings slightly too high. Now I can do it without checking with a refractometer but I always check anyway. My saltwater is generally 1.024 on the meter.

Refractometers aren’t necessary for our crabitats but for me it’s a good tool to get a feel for mixing.

Maybe I am having to adjust because over time water evaporates leaving behind dissolved solids like salt which can build up when adding more water or if all water isn’t removed during water changes. I generally try to replace evaporated water with distilled water. This should somewhat keep the parameters in check.

With “cycled” bioactive pools like a fish tank only require partial water changes periodically mainly to remove nitrate which can only be taken out my plants and or water changes. Overtime doing partial changes without adjusting for evaporation should lead to a build up of dissolved solids. Plants may be able to remove some dissolved solids as well. This build up is evident in my freshwater where I can get a tds (total dissolved solids) reading. It reads higher tds than my tap. Also some rocks can also raise tds and ph as well. I’m not sure if it’s anything to be concerned about. I can’t get a tds reading in my salt pool. I guess my meter was just too cheap. Lol.

Some people with planted tanks don’t have to do water changes at all. The walstad method (freshwater) is interesting and I’ve heard of reefers that don’t have to change water. They just replace evaporated water. But Dustins fish tanks (YouTube) does water changes in his planted tanks so I guess it depends on weather the tank can stay balanced or not. Fish load has a lot to do with it as well. I had a betta in a big bowl for 5 years. With a lot of pothos and no filters, not even an airstone. I fed 4-5 tiny pellets once a day and went months between water changes.

So let’s say you fill up your pool. Days go by and a little evaporated. You add water to bring it back up to level. Well that’s going to add more dissolved solids that didn’t leave to pool with the evaporated water. That’s why I use distilled for topping off. It’s probably so minute but over a long time of just adding tap it would build up. Is that a problem? I don’t know. When I ran my 55 freshwater (non planted) tank years ago I didn’t top off with distilled. I just used treated tap. I never had a tds meter either.

Sorry for writing a book but it’s a topic that I’m unsure about.

Re: Salt measurement check

Posted: Sat May 09, 2020 12:07 pm
by Neleono
Thanks for the help!