Stabilizing Specific Gravity

[KillBill75]

I'm Having a little trouble stabalizing my SG, It fluctuates from 1.015-1.027. I use ESV Ca+ and Alk 8ml's per day on a 35 gallon and RedSea salt. My mix ratio is 3/4 cup per gallon of RO/DI water 5gallon change every 2 weeks.
I use a hydrometer at home and at work use a Toshiba urinalysis machine in the lab.
WHATS THE SECRET!?!?!?!

[tendar]

There is no secret.
What brand hydrometer are you using? Try to get a refractometer much more accurate and you should be able to pick on up on the net for under $50.
Salt generally mixes around 1.022 with a half cup of salt per gall of water.
Top off water for evaperation should only be ro water with NO SALT in it in case your using salt mix.
Some hyrometers needs to be taped if the are swing arm as bubble some time hang on the swing arm and through off the readings.

[KillBill75]

I use a Livesea glass float type 8", And I use red sea salt.
I am going to purchase a refrac.
One more question, I dose Ca+ and Alk Buffer from ESV,I'm going to go away for a week how do I get around dosing other than using a relative?

[tendar]

going a week with out it should not be a problem. If when you get back and it is a little low just a some buffer and calk to boost it back up to where you want it but it should drop very little unless you have a lot of sps and clams that are growing well.