smileyfish

I would like to add three blennies (tailspot, canary, and bicolor) in about 2-3 weeks and i want to know in a relatively small tank if its possible to have more than one, im hoping for at least two. And im guessing to just add the three/two at the same time. But i was wondering if it would be ok to add the two/three all at once when only one other fish has been added (im not sure if thats considered an established tank?). Or should i add my shrimp goby pair first?

iloveengl

Hi smiley. Hmmm, others will likely have their own estimations, but I would say that an established tank is one that has completely cycled over a period of time, usually 2-6 weeks, and has remained steady for a at least a few months afterward. However, the length of time to cycle can vary greatly if a tank is max stocked or overstocked because the bacteria will not have much opportunity to colonize and consume the nitrate before it is killed off, thus it takes longer to cycle. If after a few months of 0 for ammonia & nitrate, and the addition of light bioload fish doesn't cause an outrageous spike, then I'd consider it a well-established tank.

My opinion is if you add too many fish at once, then you'll start a mini-cycle (this is bad), which may be disaster for any fish that is sensitive to these types of fluctuations.

Also, people have different understandings of "relatively small." Can you be more specific?

smileyfish

the tank is 40 gallons. My cycle is basically over. Im getting my first fish this friday. So thats why id wait 2-3 weeks, because i wanted to add them about second so they have a good amount of space that could be available as a little precaution to territorial issues. So if i were to add my shrimp goby pair next and maybe then my firefish. I would THEN add the blennys if the tank seems "established". But by then i would generally probabaly only have space for 2 right? or would 3 still be ok (if it ever was). I figure with territorial issues ill buy however many i end up buying and make sure theres a return policy and tell them my plan. I can watch them closely over a weekend and if there seems to be a continuing problem ill return one.