Os are interesting fish right enough...and their needs (as cichlids) goes a little beyond the "average" fish seen,and kept,by the average hobbyist.Sometimes lfs advice is good but just too general to apply to Os.
Rather than give you a bunch of links,I'll just dierct you here
to cover things like feeders,diet,filtration,and general care,and touch on a few things of notice.
Ich doesn't require
a med for treatment,just an understanding
of what it is and its life-cycle. Fresh water,elevated temp,and sometimes salt,for 10-14 days are all that's needed when caught at early stages. Ich only starts up when a fish is stressed...and sometimes meds are only more stressful....so more important to find out what is causing the stress.
Carbon is only
chemical filtration that removes foreign compounds from water,not biological filtration that removes ammonia/nitrites,and is really not needed as long as water changes are kept up...and even not then.Carbon is only good for removing meds and toxins,and can also make water testing for ammonia/nitrites/nitrates inaccurate.Carbon takes up space best used for other medias that can
harbor beneficial bacteria...it does not.
Water testing and water changes. Don't see any readings for ammonia/nitrites/nitrates...which are necessary to know. These are what tell you when
,and how much
,warer changes are needed. Safe to say that 3-4 weeks is too long and the amount is too small for what is needed to keep ammonia/nitrite at absolute 0 and nitrates at <10.
The diet. Flakes are generally not a good food for Os...to messy and makes them suck air which can cause digestive problems.The rest of the diet,as is,is heavy on proteins...and that makes for more metabolic waste in the tank and load on filtration.If a "prepared diet" is used then pellets are a better choice as food intake can be monitored and they can be cleaned up easier if uneaten.It is also important to give a very varied diet including fruits/vegetables as no one food is nutritionally complete...and lose the feeders completely,as they serve no real nutritional purpose to an O,are nothing more than an additional source of waste and filtration load,carry diseases/parasites,and (in the case of goldfish/Rosy Reds) cause vitamin deficiencies in fish (like Os) not evolved to eat them.Like research...google thiaminase.
Gravel can be cleaned with a gravel vacuum and can be done every wtaer change (or more frequent if you like).Won't require removing rocks,maybe just some moving around possibly,and will help with water readings and quality.
I'd recommend researching the filtration (what filters are they,how much do they flow in gallons per hour,what options for media),ditching the carbon,getting a good drops-style test kit for ammonia/nitrite/nitrates and using it,tightening up the water changes to 50% weekly,varying up the diet,and a little more research on the O/Featherfin (4" is 1/3rd adult size,not 1/2) to see what other needs they will require as they grow out.That should get things back to normal health-wise and actually show improvements in growth and color.
Posted same as Gerry....terribly slow typer and apparently "wordy"