Help Needed

[Hacker.neo]

Hi
can anyone help shed some light on a problem i have with my tank.
It's a 200l planted community tank with co2 injection in the day (solenoid turns off at night).
Fish list is 2 scissor tails, 3 neons, 3 cory's, 3 rummy nose tetras, 1 angel fish, 2 chinese algae eaters, 1 guppy, 3 denisoni barbs, 1 bala shark and 4 head and tail lights and a 7" plec.
Recently i've lost a gourami, 3 neons, 2 rummy nose and an angel
The Gourami had no signs at all, the angel became very listless and weak and stayed at bottom of tank and wasn't interested in food at all and ended up curling to one side.
The rest were found dead in tank but due to the lights coming on after i leave for work i'm unable to say if they were all overnight.
All water parameters are normal except a huge swing in the gh when i added the c02 system. I was also doing water changes twice a week at 12% a go but the lfs said reduce this to 20% every 2 weeks to let the tank stabalise.
When i used reaction cannister c02 system i had an airstone runing at intervals through the night.
Another thing i noticed was the temp in the morning is 2 degres lower than in day when lights have been on, would it be benefical to add a second heater to keep the heat level.
The only other prob i think it could possibly be is over feeding but i think this is more for the small fish as they are very quick and gorge themselves before the angel or bala get a look in.
Tank has been up and running for 3 months now and the fish have only started popping off in last 2 weeks
Sorry for the essay but if i give all the info then you can best advise me.

 

[fishlover500]

What are the stats in:

ammonia (shouldn't be any)
nitrites (shouldn't be any)
nitrates
ph

Could be from injecting to much C02? -not enough oxygen?

 

[Hacker.neo]

all readings as they should be
ammonia = 0
Nitrite = 0
Nitrate = 0

i use a tester to measure co2 plus i've measured ph with lights on and off and both are ok

 

[lfckopite]

all readings as they should be
ammonia = 0
Nitrite = 0
Nitrate = 0

i use a tester to measure co2 plus i've measured ph with lights on and off and both are ok

Your Nitrate reading is a bit strange you should always have some Nitrate coz ammonia and Nitrite turn into Nitrate so your Nitrate reading should be 40 or below test your tap water to see the reading staight from tap

 

[loraxchick]

the plants may be using the nitrate. i have 0 nitrate in my planted co2 tank for months.

 

[Colin_T]

All water parameters are normal except a huge swing in the gh when i added the c02 system.

Another thing i noticed was the temp in the morning is 2 degres lower than in day when lights have been on, would it be benefical to add a second heater to keep the heat level.

did you mean GH or PH or KH because the GH shouldn't change much when you add CO2. Normally the PH will drop when CO2 is added but it should stabilise. The KH will also drop due to the CO2 and will continue dropping until it is gone. Then the GH will start to drop and the PH will drop rapidly.

If the temperature is going up during the day with the lights on, it could be the lights are too close to the tank and are heating the water. If you have metal halide lights then raise them up a bit. If you have fluoros in a hood, then adding some air holes to the hood, or putting a fan on them will help prevent or limit temperature fluctuations.

 

[Hacker.neo]

All water parameters are normal except a huge swing in the gh when i added the c02 system.

Another thing i noticed was the temp in the morning is 2 degres lower than in day when lights have been on, would it be benefical to add a second heater to keep the heat level.

did you mean GH or PH or KH because the GH shouldn't change much when you add CO2. Normally the PH will drop when CO2 is added but it should stabilise. The KH will also drop due to the CO2 and will continue dropping until it is gone. Then the GH will start to drop and the PH will drop rapidly.

If the temperature is going up during the day with the lights on, it could be the lights are too close to the tank and are heating the water. If you have metal halide lights then raise them up a bit. If you have fluoros in a hood, then adding some air holes to the hood, or putting a fan on them will help prevent or limit temperature fluctuations.

The GH sky rocketed as the co2 system took a day to start working properly and i don't use tap water in my water changes.
The lights may affect the temp but it's a big tank and the heater never heats the water to what it quotes

 

[waterdrop]

What kind of water do you use?

 

[Colin_T]

the GH should not have gone up regardless of if you added CO2. The only reason for the GH to go up is if you add some mineral salts to buffer it. If you want to add a lot of mineral salts to the tank (make the water very hard) you should make up the water in a bucket, add the mineral salts and aerate the water for at least a few hours (preferably 24hours), then use that water to do partial water changes on the tank.

 

[Hacker.neo]

What kind of water do you use?

I was using RO water with electro right to re mineralise. Then i started to do half and half with treated tap water.
All the fish deaths seem to be different the one yesterday seemed to have popeye and another looked like it had bloat so i think it's stress related. Some of the bigger fish will chase the smaller ones but only within their species apart from the larger loach who chases most fish (i was considering giving him back to shop due to this)

 

[Hacker.neo]

Found my Barb dead when i got home today.
It was hanging out at the top of tank and had rapid gill movement so i dosed tank with ich cure which is the closest thing for gill flukes but it obviously didn't help.
Can all these varied deaths be related the only common thing must be stress make them susceptible to the different diseases or perhaps there is something i'm missing that encompases all the syptoms previously described.
Anyone got any clues?

 

[Colin_T]

Chinese algae eaters are territorial and as they get bigger they cause more problems. Taking one back to the shop might help reduce aggression and stress but the other one will probably take over. You might be better off getting rid of both of them and getting a flying fox or a couple of Siamese flying foxes instead. However you should wait until the fish stop dieing before you take them back to the shop. Also don't add any new fish until the tank has settled down and you haven't lost any fish for a month or so.

Pop eye and bloating are normally caused by bacterial infections. Have you added any new fish in the last 3 weeks? If so one of these might have brought the problem into the tank.

Do you gravel clean the tank when you do water changes? It can be hard to clean the gravel in a heavily planted tank but if a lot of gunk builds up in and around the plants and gravel, it can encourage bacterial and protozoan infections. A dirty filter will also cause the same problems. Filters should be cleaned about once a month. The gravel should be cleaned each water change. You don't have to clean the gravel under the plants but any areas without plants should be cleaned.
Try doing a daily 50% water change for a week, and gravel clean the tank each time.
Clean the filter (wash the filter materials in a bucket of tank water) and make sure it is running properly.
Try to make the R/O water and minerals up the day before you use it. This will allow the minerals/ buffers a chance to dissolve completely before the water is used. Possibly try a different type of mineral salt to increase the hardness. I use a Rift Lake Water Conditioner at about ½ dose and it buffers the GH, KH & PH. You could use something like that at about 1/3 strength for a general community tank.
Reduce the feeding to once a day or once every second day. Only feed half as much as you currently do. Sick fish are less likely to eat.

If you are still losing fish after a week then try treating the tank with a broad spectrum medication like "Wardley's Promethyasul" or "Waterlife Protozin". Check the directions as most medications should be used at half strength because you have Corydoras and algae eaters (scaleless fish). Alternatively use something like "Wardley's Triple Sulpha", this can be used at full strength and will do less damage to the filter bacteria.

If you can get a photo of any of the sick or dead fish it might help id the problem more accurately.