Also, to the guys who don't think dosing can sustain a tank, there's a great thread on RC about how great it is on systems 200g + . Changing systems isn't the answer - it's figuring out what's wrong with it. Dosing should work on any tank, and it's simpler to adjust individual components than reactor ever will be.

It's not the size of the tank and the amount of water that is the problem with the OP it's the fact that his tank is really full of SPS. Too many sps for the water volume.

Either he doses more and the salinity will rise, or he uses other system that won't affect the salinity. I guess it would probably be either dosing a lot more and doing a lot of water changes, or use a reactor.

Again, it's not the method, but the application. I had an SPS nano much smaller than this system with a much higher SPS load and it was doing great with dosing.

I've never heard anyone suggest such a thing before. Also, IIRC he lost many of his SPS colonies in a partial crash about 6 weeks ago.

I'm using soda ash, & just checked the ph with lights out it reads 8.2 with an elos kit.

If I had a dollar for every time I've bumped manually & raised the maintenance dose to try & stabilize I could have paid for the doser twice already

How often were you testing and manually dosing?

well that's what I was told. I never saw it either ;)

I had no idea it was even possible. So you are saying that no matter the amount of SPS and the amount of solution the tank is consuming, it should work with dosing? But if the tank require such large amount, would it not be rising the salinity too much? I never had this problem nor know anyone who does but all my friends who have a heavy SPS load are using calcium reactor and are not dosing.

Well that's probably more like if I had $10 bucks for every time. Since august it's been weekly testing & adjusting. Because that's when the dosing stop maintaing & started to push salinity. It's been a **** show since

Once a week testing and dosing should have solved the issue. Something just isn't right. Do you have a TDS meter? You're using BRS stuff right? I could go mix up say 1/4 tsp in 2 cups of RO/DI water and test the TDS of each, then you can do the same. I am using Sodium bicarbonate for alkalinity though. Could rule out a concentration issue, although I don't think that's likely. Have you tried emailing BRS? They have pretty good customer service.

I'm assuming you have double checked all the simple, easily overlooked stuff like measurements of water and chems? Have you checked that the dosers are operating properly? Maybe they aren't dosing what they say they are? Maybe measure the water in the dosing vessel, and measure again 24 hours later?

As I've told you before, the salinity in my tank slowly goes up as well. I have to add about 2 liters per week to keep salinity down. It is from a buildup of chloride. However, I also do a large 75% or so waterchange 3-4 times per year which helps flush excess chloride out. Chloride has been one of the elements that people are questioning in "old tank syndrome" crashes and general aging demise. No one knows for sure yet. We do know that in many captive reefs the chloride ions are much greater in number than in wild reefs.