Nervously deciding to reintroduce fish

[ScienceRulez]

Since Brooklynella hit the tank at work in mid July, It's been populated by invertebrates (very large hermit crabs, choc. chip sea stars, pincushion sea urchins, some little neck and cherry stone clams). about 10 days ago I introduced a horseshoe crab because it was advised that the tank I have at home, being a 10 gallon with nothing but a few pieces of live rock fragments, and a small scallop, was way too small. I'm happy to report that the horseshoe crab seems to be very happy, munching on the various bristle worms.

So now its time to reintroduce fish to the tank here at work. The tank is 530 gallons, and the parameters are finally looking good...at least to me...

As of this morning:

Salinity (SG) : 1.0225 (Aqua Controller measured)
PH: 7.95 (Aqua Controller)
Alkalinity: ~9 (API)
Ammonia: 0 (salifert)
Nitrates: .25 (salifert)
Phosphates: between 0 and 1 (API)

I'm thinking about starting out with 3 Black Tar Chromis (Chromis retrofasciata)

With the recent addition of the horseshoe crab is this going to cause problems? Is the Brooklynella gone? Before I do this, I just want some advice and possibly some hand holding, because I don't want to condemn these little ones.

Thanks.

[shifty51008]

The brook should be out of the tank but qt all your new fish or you run the risk of this hapening all over again.

I would raise the sg to 1.025 and get a better test kit for phosphates like the hanna checker, thats just more for algae control unless your gonna have corals then you'll deff want it imo

[ScienceRulez]

I have made so many changes with the tank since July, that when I stopped to think about it, its amazing.

I've added the aqua controller which will be a work in progress.
Added an auto top off with a second RODI filter system
Added a refugium
Changed from pool filters to filter socks now giving me 100% filtration (changed daily)
I saw my first bug in the main tank yesterday, so they are moving through the system
Added 50 pounds of dry base rock, so I have about 150 pounds total, next budget session I want to add another 50.

The API test kit is nearly empty, I got them when after showing some pictures earlier it was noted that I had a bunch of green hair algae. I got what they call a master test kit from API. As I run out, I've been getting higher end test kits. The local fish store however only offers Salifert and API, is the Salifert test acceptable for phosphates?

How do I up the salinity level in a safe way for the current residents? I'm guessing that it's not as easy as just dumping more salt into the sump? That it should be done slowly?

Thank you everyone for your patience.

[homer1475]

To bring up your salinity, top off with salt water instead of RO/DI over the course of a couple days.

[ZeeSparrow]

I second the above suggestions: quarantine your new fish and use salt water to top off until the salinity is where you want it.

I like the simplicity of the Salifert test, and continue to use those for everything EXCEPT Phosphate. Reading the color for the phosphate proves difficult for me which is why I got the Hanna. Jason posted a great review thread of numerous phosphate tests in the chemistry forum here.

[ScienceRulez]

Excellent suggestions, I will follow them before I get fish.

Should I continue to do twice a week water changes or would one be ok at this point? For the record, it's no big deal to do twice a week water changes but 30 pounds a week of salt can get pricey.

[shifty51008]

As long as your phosphates and nitrates stay low there is no reason to do 2 a week. Once a week is plenty