unknown betta problems...help!!!

[bcat5]

my betta started acting funny a week ago. he hides so well i can't find him and give up. he was really active yesterday and now he is right next to the heater head towards the ground. he comes up whenever its time to eat. they all know when that is. after he eats he goes right back. he doesnt even want to play anymore. i stuck my finger to the tank and usually he loves to follow it around and around. there are other fish in our 10 gallon (heated and filtered) but i don't know what to do. i condition the water and clean it. he was fine it seemed a few days ago, but now i dont know what to do. i really have gotten attached to fish and want him to live. help! please! ...if it helps ive had him for about 9 months now and only now he is showing these 'symptoms' :(

Housing
What size is your tank? 10 g
What temperature is your tank? 82
Does your tank have a filter? yes
Does your tank have an air stone or other type of aeration? yes
Is your tank heated? yes
What tank mates does your betta fish live with? tetras, cory, pleco, dinosaur birsch

Food
What type of food do you feed your betta fish? freeze dried bloodworms
How often do you feed your betta fish? depends on when im home sometimes 2-3

Maintenance
How often do you perform a water change? once or twice a month depending on the floating stuff or other things
What percentage of the water do you change when you perform a water change? 50 %
What type of additives do you add to the water when you perform a water change? dechlorinator

Water Parameters:
not tested

Symptoms and Treatment
How has your betta fish's appearance changed? fins started turning blue
How has your betta fish's behavior changed? rests near heater in corner with head towards ground, hides
When did you start noticing the symptoms? week ago
Have you started treating your fish? If so, how? no
Does your fish have any history of being ill? no
How old is your fish (approximately)? 9 months

[Bladezero]

I would start by isolating him to a Hospital tank, second thing that is to much water taken out in a single change that happens once in to long specially for that amount of fish..(in my 10g I change once a week 25%, and it has only a betta and 2 apple snails)

I've heard around alot that feeding only blood worms can cause problems,I would make his diet more varied.. He might be missing something..

It can be one of the other fish causing it, my merlin lived with tetra for months before they started trying to nibble him

Try to take a picture of him and show a picture of before might help :)

[Oldfishlady]

Sorry your Betta is not well.....it sounds like poor water quality, overstocking and poor stocking has caught up with your Betta and its just a matter of time before all the fish start to suffer....

As Bladezero post- with neglected tanks you need to be careful with large volume water changes-but this is due to the sudden extreme chemistry changes that shock the fish-especially if you also have high nitrate that lowers immune response

With proper stocked and properly maintained tanks-50% weekly with vacuum is safe.

What I would recommend now-QT the Betta in a small container that can be floated in the heated tank and start 10% water changes every 10min for 1 hour using fresh like temp double dosed dechlorinator-First add a drop of a ammonia neutralizer in the QT to be on the safe side.

The 10gal-since you don't know the water prams-you are going to need to start slow....
Start with 10% water only for 2 days and increase by 10% every 3rd day until you reach 50%...
Every 3rd day vacuum 1/3 of the substrate along with the water change-but don't move anything yet...this will come later
Once you reach 50% and have vacuum in all places that can be reached without moving anything.
Get on a regular schedule of 50% weekly with vacuum-each week move one item and vacuum well under it.
Be sure and dose the dechlorinater for the full volume of the tank-even with the partial water changes.

When a tank has been neglected-along with overstock and poorly stocked-you will have high nitrates-long term high nitrate can compromise immune response and sudden changes can shock often killing the fish.

Then you have normal decomp of organics-this creates natural CO2-this in turn drives the pH down and with low pH this converts the ammonia to ammonium-plus low pH water the nitrifying bacteria can't colonize-The sudden change in pH and the tank will crash.....and this can be fatal....

You need to re-eval your stocking
dinosaur birsch-is this a rope fish-if so...they get way too big for a 10gal...you need at least 125gal if not bigger, while they usually don't get as big in aquariums as they do in their native habitat...it should get at least a foot long...in the wild they get over 3ft long and they are not suited for a 10gal tank for more than the Qt period of about 6 weeks.

Cory-they can be kept in 10gal-but they need to be kept in a small school of at least 5 or more...10gal you are limited-plus they need a soft substrate for the barbels

Tetras- depending on the specie-some are fine for 10gal while other will grow too big and these are schooling fish as well that do best when kept in larger numbers

Pleco-depending on what type this is...if the common type-they grow well over 2ft and if a BN they get 5-6in and need at least 20gal...10gal is fine for 3-4 months.

I don't recommend that you increase the number of the schooling fish until you get the tank back in shape, re-home the rope fish and pleco...

It is important to stock fish based on adult size not current size, meet swimming, social, territory, compatibility and chemistry needs-

Good luck.....