On the profilux, are you dosing once a day or a total of that volume throughout the day?

Also, how full is your tank of coral? When my nano was full of SPS, it would drop 20 ppm Ca and 1 dKh Alk a day without dosing - likely your dosing regime just isn't cutting it.

Also, Alk of 7 dkH is fine. I keep my alk at 7 - 8 dkh (Fauna Marin supplements on a Profilux doser). I think I'm at about 256 ml (16 x 16ml) of alk a day, and 272 ml (16 x 17 ml) for Ca a day in a 100g + 30g sump (~115g total). Mg I'm using like crazy, but that's a different story.

My SG stays at 1.026, and I do a single 5g water change every week (or two).

If you're not already, I'd break up your doses to be more frequent and dose more in total. Try to test every day for a week to dial it in. Your Mg looks fine, and your SG isn't much of an issue.

To bring everything up, you may want to dose heavily for 2 weeks, then taper it off to a maintenance level. Slowly trying to raise your Ca will take weeks. Alk you probably want to do slower to avoid Alk burn, but Ca you can move a lot faster to bring it up to the 400 - 440 ppm range.

I guess your tank must be pretty full of SPS because I dose about 50ml per day in my 75 gallons and I have a lot of SPS and a clam and I don't do that many water changes. I use BRS 2 part and a marine magic dosing pump. Things are good and stable for over a month now.

If you have a full SPS tank, maybe you should look into a calcium reactor and the same for the alkalinity so that it won't raise your salinity.

KH of 7 is more than enough, and I would not go higher than 8 for a SPS tank espacially with a low nitrates level.

My Dosing is done @ 23 x 4ml doses for CA & 22 x 4ml Doses of alk currently. When I punched the numbers into the brs calculator after testing today I would need to add almost 17 ounces of BRS Ca recipe 1 to top up the CA. to 390 again That's a retarded amount to be used in 4 days, that would equal a loss of almost 126 ml per day, if I added that to the current amount I would be adding 219 ml per gal per day.Which is 4ml per gal How can that be, as there were small signs of precip when I was dosing that amount previously & not maintaining CA levels? Which would cause the salinity to go up like it was before. The maintenance dose is what I am struggling to find. It has this much coral
http://www.canreef.com/vbulletin/sho...t=76372&page=2

Yes I remember your tank and your previous post about salinity rising. Maybe you will have to use another method to keep your levels up? That is an insane amount of sps in a small tank :) I am not surprised you need to dose that much.

may wanna try kalkwasser in your ATO as well.

I was told that it was insane to try by my friend who helped me get started. But is it really possible that there is a maximum for a small tank that I have surpassed? Has anyone ever heard of this before. I really wanted it to be as jam packed as humanly possible.

Have you tried other calcium products?
Maybe u just got a shitty batch ......

maybe you should be running a calcium reactor in stead of dosing it

Ugh...I can't believe you're still fighting with this! :eek:

If it was my tank I would manually bump the calcium to about 400 (380 is fine), then in an hour bump the alkalinity up to 7 dKH (ish). Then increase the dosers by a couple mL. In 3 days repeat until you test one day and the numbers are still at 400 and 7, then you have the dosing amount right. Have you tried this sort of thing?

Once you have figured out the dosing amount you can manually bump up the levels to where you want them (say 420 and 8? whatever you want). You may need to manually bump up the levels once a week or so for the first month or two while the tank settles in. Plus, as the tank grows the demand will go up and you will have to bump the levels and the dosers. I was bumping my dosers up by 1-2 mL 2-3 times a month for a year, now I'm only increasing the dosers once a month or so.

Are you using ash soda (Na2CO3) or sodium bicarbonate (NaHCO3)?

If you're using soda ash, the additional sodium could be the source of your salinity woes. With twice as much sodium being dumped into your tank, the salinity will rise that much faster.

Also, what's your pH? I suspect it's on the higher side also since you're not getting the H+ from your Alk supplement (among other things). I know the amounts may seem trivial, but I think the combination of a high pH and high amount of CO3 and Ca you're having to add to the system may be causing your woes.

I would try switching your Alk supplement to sodium bicarbonate and see if that can change some of your fortunes. It sounds crazy that you'd need half a litre of supplement a day.....