blue jack dempseys growing slow?

[sbundy]

i went to fish store today and they pointed out something to me that kinda got me worried. i originally purchased my 2 blue jack dempseys at about 1'' to 1.5'' at least 8 months ago. they r now only at 2 to 2.5 inch each . the sales rep at the fish store told me that was not normal and that they should be much bigger at this stage. note i only feed once a day for an average of 1minute and half. could that explain it? should i feed more perhaps twice a day. will they grow faster at that point? pls help

p.s i know they r not supposed to be in there with their tankmates but they r not agressive at all and everything has been perfect!!! i feed different micro granules and frozen bloodworms once a week or so

69g fresh water
2 blue jacks
1 red torpedo barb
2 rosy barbs
2 clown loaches
1 red rainbow
1 boesmani rainbow
1 white molly

[Wizzard~Of~Ozz]

it's a double edge sword. Feeding more can increase growth rate, but it can also cause high nitrates and stunt the growth. You would have to watch the water quality closely.

[triazole]

how frequently do you change water? less frequent pwc's would lead to slow growth rates.
50% once a week is ideal, both in terms of input labor and growth achieved.

[sbundy]

i change 15% every 2 weeks

[Wizzard~Of~Ozz]

So you probably have high nitrates, Cichlids require more frequent water changes to keep the nitrates lower (they have a very rich diet). Increase it to 50% every week and see what the differences are.

[Big Ben]

you should be feeding a young cichlid like that twice a day minimum.