LFS needs help.

[Butters_CF]

Hi all;

I work at an undisclosed LFS and for the last month fish that I've been ordering have been dying rather quick, but only certain fish within a certain filter set.
- clown loach
- silver shark
- bristle nose catfish
- rummynose tetra
- black ghost knife
This week three of my ghost knives were put in an empty tank with a different filter set, and lo-and-behold their doing amazing, while the rest of the order passed on.

The water isn't that different between filter sets, the pH changes by 0.2, and thats about it.

Any help will be welcomed, and I can post any info if you need it.
Cheers
-butters

 

[Innovator]

It would help to know more about the store setup they are going into such as:

Flow-through system or individual tanks?
What size tanks?
What are you using for filtration?
Do you medicate the tanks?
Do you acclimate the animals?
Do you test the shipments for pH and conductivity?
Are you placing animals properly (prioritize region)?
What kind of water are you using (RO, city, soft, etc?)

 

[Butters_CF]

Each 'bay' has 16x 90Lt tanks and 2x 180Lt tanks. The bays have a filter that run 3x layers of sponge material (varying sizes), carbon sponge, bio-balls and ceramic noodles. The filters have automatic refills using a float valve and pre-filtered water. Each tank is supplied with air and can be run separate from the rest of the bay.

Upon arrival each bag is acclimatized for 15-30mins, after that the pH is tested, if the pH difference is too great the fish are placed in a 'doctor tank' and are adjusted over a few days.

As for placement, these are part of our 'core range' and have not changed in a great number of months, if not years.
Bristle-nose catfish - Congo tetra
S/sharks - scissor tail ras
C/loach - pristella tetra
Rummy-nose - hockey stick tetra
Ghost knives - rosy and lemon tetra

I run stress-coat through the system after the fish are added.

The water the fish arrive in is not added with the fish, due to the high levels of ammonia experienced with several hours of freight.

The problem bay is our 'community section', so it has all our tetras, barbs, cory and a few sharks and gourami.

 

[Butters_CF]

May have solved the problem...

There was several large bristle-noses in the filters sump, under all the filter material... Several largies and maybe a hundred littlies...

Some of the babies managed to get through some of the system and blocked up certain lines - the worst affected tanks had the dying breeds.