In Short:
I have salinity at 45+ ppt. How can quickly can I take it down to 35? Should I be water changing with RODI water or low salinity water.
In Long:
I have been running a reef tank for around 5 months now. It's a reefer 250 (55g). Over time I have gradually tried to add corals. With a few minimal exception these have all died. As it stands living I have 2 GSP frags, a kenya tree frag, and 5-6 very closed up zoas. I also have a couple of cleaner shrimp, a convict Blenny, 2 small clowns, a lemon damsel and a firefish.
Over the past 3 months I have tried adding corals 4-5 times. In some cases they have done fairly well, I had a hammer and an elegance coral that seemed to be thriving for a while. In others though, they just died. The few SPS frags I tried to add died within 12 hours. No zoa has ever opened more than 1/3 of the way. In response to this, I tinkered far more than I should have. In terms of flow, placement, lighting and nitrate/phosphate removal. I always assumed it was my basic chemistry but on multiple test kits showed 0 Amonia/Nitrite and close to zero Nitrate/Phosphate. Salinity always showed around 33.
Given my salinity had always been a touch low, I decided that could be my cause. Over the course of 2 weekly water changes I raised it from 33-35. At that point what few corals had been prospering died.
At that point I almost completley gave up. I was on the verge of just keeping fish. But I read online about people with the same refractometer as I have having to calibrate it frequently. Having never done this I decided to give it a go. I bought a 35 ppt test solution and put it into my refractometer. It came out as 20. Assuming I had a bad batch, I ordered a second sample from a different brand. 20. Reading online I saw that a lot of people simply calibrate to RODI water. I tried that. -15. It was so out, the calibration dial wouldnt even let me correct for it.
So here I am. I've ordered a new refractometer which should come tommorow. But I need to work out what to do. My salinity is currently running somewhere in the 45-50 range. What are my next steps?
As a small aside, I realise that I have made almost every clasical rookie mistake possible here short of adding 3-4 tangs to my tank. My aim once this is sorted out is just to run the whole thing stable for a month or so before doing anything else.
www.hamzasreef.com
