Help ID- All 4 big cichlids died while on vacation!!

[Oscar Mike]

So I went to mexico for a week and when I came back my 100gal tank was cloudy white water with all 4 of my biggest fish dead! Including the big male red dragon in my avatar, 2 female flowerhorns and my 2 year old midas I have no idea what happened, before I left I seperated all fish with egg crate dividers and added a 14 day weekend feeder block for each fish. The tank was going for a few weeks and I had a dual hang on filter and magnum 350 canister filter with ammonia remover in the carbon. I had the water tested and besides a high ph everything was fine except the ammonia level was above 6.0, which I assume was because of the decaying fish. The only thing I can think of is a rock was on top of the midas' feeder block when I emptied the tank so if it happened early into the trip he wouldnt have had food for 5-6 days, but I think he was big enough to last that long. ANY advice would be appreciated

 

[Chefken]

THE tank was going for a few weeks??? WHat were the water parameters before you left? did you do a large water change before you left? I doubt the bio on your tank was able to handle the food you left.....once one fish died the water was shot and the rest followed....just a guess!

 

[Oscar Mike]

Thats what I thought too... actually I siphoned the water directly from a running 60g to the 100g I upgraded to, and then added bacteria and ammonia/chlorine remover to the additional 40g. but the tank doesnt have gravel because a breeder I know said it was bad for breeding and their colors would mix...

 

[Chefken]

The water has nothing in it for the bio load. We all spend a fortune keeping out water clean! THe filter, media and tank itself hold the bacteria you want....no substrate puts the burden on the bio in your filter.....Takes two months or so to cultivate for a cichlid bio load....

 

[Oscar Mike]

man thats what Ive been worried about, I cleaned out the tank and added a sponge filter, but I have a pair of dovii and some flowerhorn fry in it right now, do you think I should add the gravel or will it mess up the fh colors?

 

[Chefken]

I like sand! YOu could go white or as dark as you like! I do not believe your colors will be affected as much as the diet will dictate....

 

[Oscar Mike]

I like sand too, I wanted to get black sand for my 90g and black for the 100g but its expensive and i am currently out of funds... I have about 60lb of black/red gravel in a bucket from my last tank but i was worried it would cause the rd flowerhorn's colors to mix not to mention how dirty my water will get, but they actually look a little faded right now with the bare glass so i might go add it right now