Off to a bad start...

[jblakeh1]

I'm new to marine aquariums, and specifically got one for a few green spotted puffers... I had one in a brackish tank in college many years ago and decided I wanted to get some more.

So last weekend, I got a 40 gallon aquarium, set it up according to the pet shop's instructions regarding the salinity, and temperature, and added the sand with 'good' bacteria in it. My only concern with my advice there is he thought I should cycle the aquarium with damsel fish rather than live rock. I'd read online that that was not really necessary, but I followed his advice anyway.

Early in the week, I went to another pet shop and purchased some live rock, thinking it might help cycle the tank faster. I've monitored the salinity, Ph, nitrate and phosphorus levels several times this week, and as of this morning, they are within acceptable ranges, according to the test kit instructions.

Here's the problem: three of the four damsel fish have died, without any outward symptoms or unusual behavior. I was nervous about putting fish in the tank so soon, and now my fears have been justified. Now I am concerned about buying any puffers (not that I would for another 2-3 weeks), not knowing what caused their deaths.

The remaining damsel looks and behaves normally, but so did the others, so I'm hesitant to say he's healthy... any advice?

[jblakeh1]

I just saw the big red warning requesting specifics. Here is what I recorded this morning:

ph 8.2
phosphate 0
nitrate < 10 (mg/L)
gravity is about 1.023, up from 1.022 when I started - I've been gradually adding distilled water over the course of the day.

[busybones]

Welcome to the forum

I too am unfamiliar with SW tanks so I do not feel comfortable giving you advice on the cycling aspect of the tank. However I'd like to say that in a 40 gallon tank you can only house one GSP especially with the live rock, decor, and substrate. I'll add some links to a few of our articles about GSPs..

(Introduction to Green Spotted Puffers)
library/puffers-in-focus/an-introductio ... d-puffers/

(GSPs puffer Pedia article)
ug.php/v/PufferPedia/Brackish/T_Nigroviridis/

[Pufferpunk]

Although it is good to see you have some nitrate, what you really need to know is ammonia/nitrite. How much LR did you add? What makes you think that sand is "live"? For a 40g, I'd stick with 1 GSP, unless you plan on upgrading in a couple of years.

[jblakeh1]

Thanks for the responses.

The bag of sand literally says it contains live bacteria, along with the claims 'no cycling needed' and 'add fish immediately:' http://www.livesand.com/

I added about 6-8 pounds of live rock.

My plan was to start with two small green spotted puffers and eventually get a larger tank. The puffers I've seen at the pet shop were less than an inch long, so I think two would be comfortable in 40 gallons for 9 months.

From what I've read, it was also my understanding that monitoring ammonia was important, but the guy at the pet store recommended pH, nitrate and phosphorous tests only, so I put the ammonia test back on the shelf.

So much of this is subjective, it's really difficult to get a grasp of what's going on, and why the damsels died. They were both content yesterday, then this morning one was face-planted in the sand.

[LilGreenPuffer]

In all likelihood, the bacteria in that sand was dead when you got it. It needs tons of oxygen and an ammonia source.

Ammonia and nitrite MUST be monitored, especially in new tanks. Nitrate is the least harmful by a long (very long!) shot.

Do an 80% water change now. After that, here's some important reading for you to do - you should pretty much disregard everything that pet store person says from now on and do your own research:
http://reefcentral.com/forums/showthread.php?t=1031074

[jblakeh1]

Thanks for the advice. I'll take a look.

[jus85411]

they say the bags of "live sand" are a scam. like lilgreenpuffer said, they need oxygen and some source of ammonia as well as some sort of circulation for the bacteria. you should buy regular dry aragonite sand, takethe money you would spend on live sand and just use it for live rock to seed the sand

[jus85411]

also, what did you use to dechlorinate the water? your best bet is to fishless cycle and put a few pieces of shrimp in a stocking or mesh bag and let it sit in the tank with the filters running. you have your source of ammonia and its just as good, if not better than using fish. the shrimp will begin to decompose, creating the ammonia, and your cycle will be the bacteria trying to catch up with the ammonia being produced in the tank. using a few pieces of shrimp will probably get you pretty close to the amount of ammonia a puffer will produce.