Justcrzn

Hello there,

This is my first post so be gentle

Type of fish: Cichlids African & American
Symptoms: Fish loosing colour and basically look unwell have lost 50% of stock over about 2 years.
Current Fish Stock :

2x Red Devil 20cm, 10cm

1x Red Zebra 12cm

1x Electric Yellow 12cm

2x Electric Blue 12cm male, 10cm female

2x Polleni 15cm

1x Venustas 20cm

1x Maingano 12cm

1x Jack Dempsy 15cm

1x Cobolt Blue 12cm

1x Bristle Nose 10cm

1x Red Tail Black Shark 10cm

1x Catfish 15cm

1x Trouphues Bomb 15cm

1x Euchilus 12cm

3x Fuelleborni 12cm

Tank capacity:  400lts 
Type of Food fed: Hikari Gold (50% floating 50% sinking)
Feeding frequency/amount:  approx 130 pellets once per day
Substrate: Crushed Coral
Type of filtration: 100ltr sump + Phosphate Nitrate filter
Frequency of sump filter cleans: once per month (sediment vacuumed and filter sponges washed), (media balls rinsed once per year (with tank water))
Frequency and % volume of water changes: 150ltrs weekly 30%
Last water change: last weekend
PH:  8.3
KH: 10
GH: ?
Nitrite: 0
Nitrate: 40 - 80
Ammonia: 0
Phosphate: ?
Water temp: 27
Medications used recently to date: Intestinal Hexamita Clear
Any recent changes..new fish/filters/power outages etc etc: None

I have kept Cichlids for about 2 years now.  Unfortunately I lose fish with what looks like sunken belly (especially the peacocks) In the past I have treated with Intestinal hexamita clear but didn't notice any improvement.  All fish are although feeding well.   The dilemma I am in, is that I have always had elevated nitrates (40 - 80) and know that if I feed more this will only get worse.

My questions are :

1 - Am really overfeeding ?

2 - How can I reduce nitrate levels ?

3 - Do you think what looks like sunken belly is due to underfeeding or indeed an internal parasite, if so any recommended medication.

I have attached a photo of my tank set-up

 IMG_2865.JPG   123.33KB   4 downloads

Appreciate any help.     Rob