Originally Posted by coco1963
The tank is 29 gallon, filter is just a regular filter with 2 size C filter cartridges & seperate powerhead. About 20 lbs of live rock. Coral on the bottom and sand on the top. I am ashamed to say that because everything was going well and the fish were acting normal we didn't check anything before we got the new fish and they're so pretty you just want 1 more . Had: Sailfin Tang, 2 percula clowns, royal gramma, scooter blenny, snails, hermits, coral banded shrimp & Urchin. Added: porcupine puffer, pygmy angelfish, horseshoe crab, sand sifting cucumber & brittle sea star. (most added for tank cleanup) The purple urchin didn't die till later, the cucumber didn't die till last. No Anemones or Sea apples. I'm sure it's our fault for overloading and not being consistent with the maintenance. We're going to drain it, throw away all the old coral & sand. Put the LR in a bucket of saltwater to sit for a few days till we're ready to start anew. Unfortunately we're learning by our big mistake. I added copepods & live brine shrimp for food & grape Caulerpa MACRO ALGAE last week too, do you think any of this was a problem?
It sounds like you had a decent system going with livestock and equipment. Obviously the tang shouldnt be in a 29 gallon tank and I dont think the puffer or horseshoe crab should either. I dont know how grown any of these fish are but the utter meltdown of the tank honestly sounds like something toxic was added - weather from within the tank or an outside source. From within, I could only think that the cucumber may have caused it but if it did indeed died last then I would rule this out. Are there any outside toxins that could be attributed?