Green Reef Chromis in even gougs

[john0087]

Hi all,

I have always heard that chromis should be kept in od number groups. So yesterday I bought 5 very small chromis for my tank, sizes from 1/2" - 1".

I drip aclimated them for 2 hours with the light off. They were in the tank for 1 hour then I turned on my actinics, 1 hour later, the daylight s went on. THe lights were on only for 3 hours.

Later in the afternoon, they all ate Ocean Nutrition Formula one flake very hardily.

This morning, one has dead.
The other 4 eat the same flake very hardily

Water params are this morning were
Ammonia 0
Nitrite 0
Nitrate 0
PH 8.0
temp 75

This is the first fish that I have lost ever 1 day after acclimation.

The question is now, 3 of the chromis are shoaling nicely and 1 is hidding in the rock where the all "slept" when th elights went out.

Should I be concerend. Will they be ok with 2 pairs or should I get a 5th again. Once the lights go on, I will see how the fourth fish reacts. I can see him and he looks healthy.

Oh, the dead fish was a red spot on the rear body. He was the smallest of the 5 and was always getting seperated from the shoal, even though they would all go and try to find him. I am thinking stress and maybe a little bit more careful acclimation with such a smalll fish would have been better. I don't know, I am pretty careful at the process.

Thanks

[Pescaiolo]

Your pH is low. You need to try and bring it up to 8.3 to 8.4. I am not sure if it caused the death but it could be a very good possibility that a sudden change in water chemistry could cause the fish to stress to the point of death.

[john0087]

Originally Posted by Pescaiolo

Your pH is low. You need to try and bring it up to 8.3 to 8.4. I am not sure if it caused the death but it could be a very good possibility that a sudden change in water chemistry could cause the fish to stress to the point of death.

Yeah,

I know the PH was a little low, it usually climbs to about 8.2 -8.4 after the lights have been on for a while. I am not runing a fuge yet, so I do have a slight swing in Ph between the mornings when there is no light and when the lights finally turn in.

That may be the case. I have never had a problem before with the Ph swings and frim what I understand 8.0-8.45 is an acceptable range but I will continue to monitor it.

UPDATE

The fourth Chromis swims in and out of the hiding place. I will continue to monitor.

Any comments on the 2 pairs vs odd numbers?

Thanks

[CarmieJo]

I have always heard odd numbers

[Phurst]

I know a lot of people, myself included who have never had good luck keeping chromis in groups. My original group of 5 is down to 2, and know several others who have had the same experience. I have one dominant chromis who ran the others to death.

[veriann]

looks better with odd, at the end of the day, they will sort their own hierarchy

[john0087]

Originally Posted by veriann

looks better with odd, at the end of the day, they will sort their own hierarchy

Yeah,

After observing them today, they definately have started to sort out the hierachy. the fourth one, which happens to be the largest, hides a lot, but has been swilling with the rest while the 3 chase each order.

Right now with the lights off, they all go to same underhang and stey together tightly.

So I guess the queston now is, do I pick up another small chromis tomorrow or do I wait? Would it be better for the goup to let them sort things out now and add a new fish after, or do it now while their shoal hierachy is still forming.

I think it might be best to add the 5th one now.

Thanks

[john0087]

Originally Posted by Phurst

I know a lot of people, myself included who have never had good luck keeping chromis in groups. My original group of 5 is down to 2, and know several others who have had the same experience. I have one dominant chromis who ran the others to death.

Wow,
you may be right. This morning, my "shy" fourth one is missing. I looked pretty hard and could not find him. I fe dthem a little as I have heard chromis eat a lot and the three came out ot feed, but the fourth one was nowhere to be found. I looked pretty good with a flashlight.

I guess I am going to have a shoal of three chromis.

I'll update tonight when the lights are on.

Thanks

[SoCalReefer]

I've had my four chromis for sometime now, it seems when they were first introduced they tended to die off. It might just be a social thing that fish get accustomed to. maybe when in small volumes of water the school just gets too stressed and weaker members die, i dunno. but i have seen a pattern. Once you have an established group in your tank, try to introduce another member cautiously and only one at a time.