How many chromis to stock?

[alex277]

I've been keeping freshwater tanks for about 15 years and have set up my first saltwater tank. The cycle is now completed and ready to start stocking, going to order some fish tonight or tomorrow. I'm not entirely sure on stocking levels for saltwater, as it is different from freshwater, so any insight would be helpful! The tank I have is a waterbox 220.6, the display is about 170 gallons (6'x2'x2') with a sump that holds just shy of 40 gallons. I planned on stocking:

1 purple tang
1 yellow tang
1 blue tang
1 foxface
2 clownfish
5 lyretail anthias
(?) green chromis
1 diamond goby
1 fromia star

This doesn't include clean up crew - I will be getting crabs and snails in addition to the above mentioned My primary question is how many chromis I should add in, based on the size of this tank and with respect to how many fish are going in other than them. What would be a good number to add? I was thinking 7, 9, or 11? Or would more be ideal? They are gonna be the first, along with the pair of clowns, going in, so I'm trying to get an idea of how many of these guys I'll be adding before starting to buy them.

Additionally, does the above stocking list look about right for a tank this size? Too many fish, or could I maybe fit a bit more? Like I said I'm still trying to gauge appropriate stocking levels for saltwater. Any help is greatly appreciated!

 

[Uncle99]

In that tank, 10 ish just as you thought.
They are more successful in larger tanks like yours and high numbers spread that aggression out even more.

 

[doubleshot00]

1 purple tang
1 yellow tang
1 blue tang
1 foxface
Add these last and at the same time. Maybe in about 2 months after you added the others.

Add the clowns then after a few weeks add 3-4 more.

Add as many chromis as you want you’ll probably only end up with 3-5.

 

[PatW]

Green chromis are weird. Mine always murdered each other. Some people have better luck. Also a mix of chromis species might work but that does not give you the uniform look for aggregating fish. You could try 5+. Your tank will probably support that many or more depending on your husbandry. A lax husbandry and it might be pushing it. But if you stay on top of things and have filtration, skimmer etc, you should be fine (If they don’t murder each other).

 

[FIN&BONEZ]

Ive always when wanting a successful school of chromis added them after the tank was heavier stocked. If your planning on cycling the tank with them I would only do 1 or 2 at first and the rest later. They will slowly kill each other if they are left in bigger numbers all by them self. My school is more worried about staying out of the way of the achilles then each other if you catch my drift.

 

[sbbk]

Green chromis are weird. Mine always murdered each other. Some people have better luck. Also a mix of chromis species might work but that does not give you the uniform look for aggregating fish. You could try 5+. Your tank will probably support that many or more depending on your husbandry. A lax husbandry and it might be pushing it. But if you stay on top of things and have filtration, skimmer etc, you should be fine (If they don’t murder each other).

Chromis tend to get killed off. I've had green and bi-color and blue chromis together, 7 total, and eventually 1 bi-color became dominant and killed all the others. He then lasted over 5 years with pretty aggressive fish. Good luck with a school.

 

[Ancient Mariner]

I have 7 in 100 gallon tank for 9 months. No losses, no aggression to each other (just pecking order nudges), no aggression towards others. They have doubled in size. I do have a heavy SPS reef with large branch acros which they love and hide in. They school tightly together and look great. It is possible they are doing well and school well because of the physical environment with high flow and high coral hiding places.

 

[exnisstech]

Added 7 chromis and ended up with one. I did this twice and both times ended with one. 6 ft tanks, a 150g and a 180g.

 

[ISpeakForTheSeas]

Yeah, I've heard with schooling/shoaling fish (including green chromis) that you need either a healthy dose of luck, or a large number of fish (9-11+ fish total, with an odd number of them being the recommendation I've gathered from various sources). I'm sure there are other variables (such as food availability and quantity/quality, as well as other tank inhabitants) that come into play with determining if the fish will murder each other or not, but diluting the aggression with a large number of fish is a good place to start.

 

[Bucs20fan]

Anthias school much better among rocks than chromis do, yes they get larger and are 4 times the cost each, but they will establish a pecking order and wont murder each other one by one.

 

[Floyd-]

I had about 6-7 Chromis in my 150 gallon display. None were killed in the year that I had them. I just got tired of them in the tank and rehomed them. BTW, I can say they were about the hardest things to catch in a tank this size.

 

[ReefCheef]

For what it's worth I have a 450g display and a 200g sump. I have 10 lyretail anthias, 12 chromis, a fox face and a white tail bristle tooth tang. Even in my big tank it is starting to feel pretty crowded to me. Guess it depends on your preferences, but to me having a tank stuffed with fish doesn't look natural or bode well longterm for the bio filter. I'd probably go with 7 if I were you. If you feed them well they get surprisingly big and thick. If you want the fish to school it's best to have larger fish and larger schools around them so they feel a need to school for security. My chromis schooled like crazy when I had 6. When I upped it to 12 they rarely school now because they are the biggest group in the tank and feel more safe.