saltinity and temperature

[JoshsReef]

well my live rock is due in on wend from liveaquaria ( if anyone has bought rock from them i would like to know how it was) anways i am using a cheap instant ocean hydromoter and it is giving me a specific gravity of around 1.024 and my temp is running bw 79.5-80.1. should i lower my temp before i get my rock or try and keep it stable where it is at. i plan on seting this aquarium as a reef set up and heard that around 80 was better than bw 72 and 78 for a reef tank. also with the temp where it is how accurate is my hydromoter. i cant really afforod to put anymore $ into this unit at the time ($1500 in a 75 gallon already) so this hydromoter is going to have to do

thanks in advance

 

[tecwzrd]

Any temp around 75-82 is fine as long as it's stable. If you have a floating hydrometer then IME they are more reliable then the swing arm type. The swing arm hydrometers are easily dropped/bumped and can easily give inaccurate results.

The floating type can also be off but typically will always be off the same amount and you can check the results of your floating hydrometer against a refractometer which is going to be most accurate and adjust accordingly.

Of course money wise a reef tank will always cost more down the road (stock/food/salt/ect) and before you spend money on the other items I'd get a refractometer to ensure the most accurate SG.

 

[MT79]

When using those plastic swing arm hydrometers it's best to keep your SG in the middle of the acceptable range. 1.024 is a good number to be at w/ one. That way if the hydrometer is off you will not be too high or low. Basically leave some room for error if you doubt your equipment at all. Be sure to wash it after every use w/ fresh water and measure on a level surface otherwise they can be very misleading. FWIW my two IO hydrometers where only off by .001 when compared to a refractometer.
After you install your lights you may have to adjust your temp to avoid large swings between night and day. If your lights heat the tank during the day, which is an issue more w/ high light systems esp. those w/ MH, you will have to adjust your heaters so the tank doesn't cool too much at night. Keep temp swings under 2 degrees daily. 77-84 is fine, as long as it's stable. IMO 80-81 is ideal.
HTH

 

[MT79]

PS-

($1500 in a 75 gallon already)

I just wanted to second what Tecwzrd said about investing in a refractometer. Right now you have $1500 worth of investment riding on a $8 hydrometer. As the saying goes, the chain is only as strong as the weakest link. Plastic hydrometers should be replaced every 6 months or so as well, so the cost overtime is higher.
Good luck and please don't hesitate to post any questions you may have in the future.

 

[JoshsReef]

well my major concern is that my live rock is going to be here wen. i can get a more accurate assesment of my salt level before i had fish but i want to have it at least in the respectable region by tomorrow. i forgot to season the hydromoter before using it so i have it soaking in my aquarium right now. when i used it before puting into the tank to soak it was read just over 1.023. should i be ok for live rock wen

 

[tecwzrd]

Your lr is going to have die-off regardless of your SG reading but 1.023 is fine. Are you using your lr to cycle the tank?

 

[madhatter208]

Definitely get a refractometer.
I had the cheap plastic hydrometer and it was reading 1.022 after I added the sand. Before that it was reading a 1.025. I rinsed it, dried it, double, and even tripled checked for air bubbles. Thought to myself how the hell can it go down that much. So being new and dumb i added more salt and it cont to stay at 1.022.. more salt.. 1.023.. hmm ok this aint right so i got my refractometer and woow.. 1.028 opps.
The hydrometer now sits in a dark hole never to be used again. After putting in 1500 into your system whats an extra 50 bucks. It comes in a nice heavy duty case for storage and will last you a life time. Learn from my mistake hehe

 

[melosu58]

As stated above the key to temps is stability. Try to keep the temps in a certain place and keep it there. Where you have big temp swings is where you have problems. I agree also use your LR to cycle your tank.