fresh water top off ????

markvanderwoude · #1 12/21/2006, 02:09 PM

the salinity level is 40ppt and I need to decrease it to 35ppt how much fresh water can I add per day to lower it?

the water seems to evaporate just as fast as I add fresh water

when you add water do you only add fresh water? need a little advice

geekreef_05 · #2 12/21/2006, 02:20 PM

whoa, dude....assuming your talking about your 75G display + 40 fuge (115 total vol)....

(1) Yes only fresh water is added for top off. No salt water. If you put additives into your reef they should generally be added via this top off water as well.

(2) You should be able to add ~4 gallons per day without any issues in your reef. Although when I say 4 gallons I mean it should be added slowly. ie. dripped into the tank over the course of a day. The best solution is for you to get an auto-top off system. That way your tank is far more stable.

(3) The target range for salinity is not 35ppm. Try to get btn 22-25ppm. Thats far more comfortable for your inhabitants.

(4) You should be topping the tank off daily to ensure the most stable parameters possible. Dont wait until you have to put in 4 or more gallons at once. If you have sensitive critters, like anemones or starfish, they'll be super super stressed due to your reefing methods.

jgoodrich71 · #3 12/21/2006, 02:34 PM

Quote:

Originally posted by geekreef_05

(3) The target range for salinity is not 35ppm. Try to get btn 22-25ppm. Thats far more comfortable for your inhabitants.

I think you are confusing specific gravity with salinity. It should be 35 parts per thousand (not ppm), or the specific gravity should be about 1.026.

eckrynock · #4 12/21/2006, 02:43 PM

Quote:

Originally posted by jgoodrich71
I think you are confusing specific gravity with salinity. It should be 35 parts per thousand (not ppm), or the specific gravity should be about 1.026.

That is correct.

markvanderwoude · #5 12/21/2006, 02:50 PM

thanks

jgoodrich71 · #6 12/21/2006, 02:59 PM

Everything else stated seems OK information. Just as an example, my 65 gallon evaporates 5 gallons every 2 to 3 days. So I am adding that much fresh water every couple of days.

Paintbug · #7 12/21/2006, 04:18 PM

to lower the SG you will need to remove water from the tank, then add RO water or saltwater made up to a lower SG even. top off with RO water as needed as well. but if you only top off with RO water it wont drop your SG.

rooroo · #8 12/21/2006, 04:23 PM

Do a decent sized (25%) water change every day with the SG of the new water at the correct level. Do that until you get your salinity to where it should be. From now on when you top off you use only fresh filtered water, but when you do water changes you replace the water you removed with new salt water.

Just think of it this way...

salt does not evaporate with water. So as long as its just water evaporation, you only need to replace the water since no salt has been removed. When you remove water from the tank, like during a water change, you take the water with the salt in it, so you need to replace the salt too.

yakfishin · #9 12/21/2006, 04:34 PM

If you're using a protein skimmer, don't forget to take into account that the skimmate has saltwater in it. If you just keep adding freshwater to make up for the loss of water your skimmer pulls out as well, then eventually your salinity would drop- slowly but surely.

BiggySmalls · #10 12/21/2006, 06:39 PM

what if i have low salinity? should i get water and mix salt in it and add it slowly to the tank. the sg is at . 1.018

Paintbug · #11 12/21/2006, 07:51 PM

raising the SG can be accomplished by adding salt water as top-off water. just remember to do it slowly. you dont want to change the SG more that .001 +/- a day.