fishes in shock and BGA


Junior Poster
May 8, 2008
Hope a few gurus could help me out, seems im plague again with problems.
Going to detail every regime, hopefully some bros could help pinpoint my
critical errors.

Tank Dimensions: 20cube 10L

Lighting Intensity(No of Watts) :12Watts
No. of hours your lights are on :9 hrs

CO2 Injection Rate (bps) : 1 bubble per 3 sec
Type of CO2 (DIY/Cylinder) : pressurised
Method of Injection (e.g. Diffusor/Reactor) :atomizer
Dropchecker used : ADA drop checker with 4/5dkh solution; green-dark green

Liquid fertilisers Used/Fertilization regime:
i prick a needle hole on the sechem bottle sealants and dose according to this drop.
2x drops sechem nitrogen - 3 times per week, mon/wed/sat
1x drop sechem phos - 2 times per week, mon/wed
1x drop sechem trace - 2 times per week, tues, fri
1x drop sechem potassium - 1 time per week, thur
1/6 teaspoon sechem equilibrium - 1 time per week, sunday during WC.

Type of Filter: gex 250l/h ohf
When was the filter last washed : weekly siphon of food, biomedia soak in tank water to remove excess mulm twice a week.
Filter media used : Mr aqua ceramic ring,Biohome plus, wool pad
When was the media last changed : added mr aqua 2 weeks back, soak 2
weeks in water before adding to canister.

Age of setup : 3 month +

Water change frequency : 1 week once
Amount changed :30%
Water top up per day : 500ml due to 9cm diy fan.

Water surface movement (None/gentle/turbulent) : gentle
Circulation (None/gentle/turbulent) :gentle

Tank Temperature :26-28C

Chemical Properties (current)
KH (dKH): 0
GH (dGH): 0
pH :5~6.6
Nitrite :0 ppm
Copper : 0 ppm
ammonia : 0ppm

Bioload (Number and type of fish and plants) :
Lushgrown taiwan moss as backdrop with japanese hairgrass. [5 months]
3 boraras brig and 2 snails. [5 weeks]

Feeding : Hikari micro tetra pellet
method of feeding - 3 micro pellets per day, pellets are flatten with tweezer, split in half then feed to fish. Food gets eaten immediately. Minority of food however does get sucked up the inlet if they can carried away by the current.

-sun. wc. change bps -> 1 bubble per 2 sec instead of 3. lower airstone power by half.

-mon. All the boraras reverted back to pale from red. They have been red for about 3 weeks, fed them as usual, no change. dropchecker green.

-wed. sudden outbreak of bga on the 3rd day, 2-3 strands of hair algae [2-4cm]. The bga coverage on soil was bad as i usually get this at the end of the week. Tested water, ph 5 even though dropchecker was only green, ammonia/nitrite=0ppm. Remove bga infested soil. Trim away moss with hair algae. Perform water change 30%, siphon water to bucket, soak bio ceramic rings in water in the bucket [exisiting tank water].

-thur. boraras still pale, notice stressful behaviour such as swimming frantically up and down the tank wall and jerking frequently.

-fri. Lost one boraras, have no idea how it got siphoned into the inlet as the holes are pretty small and i had the upslope of the ohf blocked by a course sponge. Its head and body was split in half... I took out the moss and noticed browning on the other side of the lush grown moss. Took the biomedias out temporary and place them in the bucket, siphon out debris from the ohf, put everything back in and fill the canister with aged dechlorintated water. Biomedias were not washed.

As of now, boraras still pale, 1 swimming frantically up and down the tank
walls. 1 stays only at the tank bottom. Guess i will lose both by tomorrow.
Nerite snails are fine and plants are growing well with bubbling.

I do not know if its poisoning, the water used for wc have problems, the water used for top up has problems or others. I have also no clue why everything seems to be growing well, i still have BGA and it grows like nobody's business, maybe its my mosswall "decaying" on the other side or overfeeding, but still ammonia test still shows 0ppm.

Appreciate some help. thanks


Junior Poster
May 8, 2008
posting some good comments so far..

You should stop adding the CO2 for now and aerate the tank to see if the fish health improve. You can always get the algae off and plants to grow back but you cannot re-animate fish though. For a 10l tank, 1 bubble per 3 sec of CO2 might be tad too much but not sure if there is anything blowing off the CO2 fast in your tank or not.

Peter Gwee


Junior Poster
May 8, 2008
my lastest post this evening.

surprisingly, didnt lose any boraras today. They were still active, but same, all 2 of them are behaving oddly, swimming frantically up and down the tank walls. Both of their colors are now pale but eating properly.

BGA sprung right back after being cleared on wednesday, they are developing slime now.

KH =0 means no buffer for PH swings. This is understood. Nothing new in your post.

Drop checker is reading green -> to darkgreen. 3 seconds for 1 bubble too much ? I have increased the airpump back to full strength, probably that explains why i didnt lose any fishes today, but not sure what they are stressed about as there is nothing new i have changed besides those I have listed from monday.

I plan to move the fishes to a 700ml temporary tank with existing tank water tomorrow during my wc while i vacumn the soil again after removing the HG in that area.

question ?
-Do i need to re aclimate them again for a couple of hours before introducing back to the tank as I may need to do a 100% water change tomorrow since i need to plant back the HG before adding water. Is this advisable or should i put it off to avoid shocking the fishes ? and go for just a 3 day black out with good aeration ?

I will wait for your helpful advise before progressing then. Many thanks

5-6.6 PH is a range which exhibits my usual PH.

it should be BGA as i recognise the green slime on my HG again.


Guru Class Expert
Jun 8, 2007
Do you have soil substrate? I had nothing but problems with soil substrate, bga was a continual problem and I finally had to dismantle the tank. Anything decaying will also cause it (plants etc.)

You could change your drop checker fluid to be sure it's correct.

If you remove co2 to see what happens to the fish, I would keep the light off as well, this might help get rid of your bga. Keeping the light on while removing co2 could cause more major algae problems.

If your tap water has 0 GH and KH you might be ok replacing evaporated water that often, but keep in mind that anything in your tap water will be building up to much higher levels with that evaporation happening. If you can, you should only replace evaporation with distilled water.


Junior Poster
May 8, 2008
thanks carissa, i am currently using the gex soil, didnt have this problem initially but later.

I had help from AQ indicating that i m actually underdosing ferts, the required ppm for my tank was
20ppm nitrate
2ppm phos

i was only dosing less than 1ml per week each.

I have been going through tom's solutions to managing them with blackout.


Junior Poster
May 8, 2008
seems i didnt lose any fishes from last week and they are fine except im not sure whats with the erratic behaviour. I stopped ferts regime for 3 days and noticed they were back to red.

I managed to clear my bga from the soil, dose nitrates 1ml of both sechem nitrogen+phos and will continue to keep them at 20ppm + 1.5 ppm till end of the week and observe.


Junior Poster
May 8, 2008
Fishes are back to a robust red again after making the following changes. Water looks surprising clear as well.

-Substract cleaning of BGA and replanted all the HGs
-removal of bga infested wool filter and clean biomedia in existing tank water
-replace wool filter with new gex carbon pad
-rearrange biomedia to biohomeplus ->gex carbon pad -> mr aqua ceramic ring
-added 1ml sechem stability to biofilter after wc.
-aclimate boraras back into tank after 12hrs with 20ml of new tank water injection per 30mins interval
-redo fert regime to target
20ppm NO3 with 1ml dose 3x per week
1.5ppm PO4 with 1ml dose 3x per week
0.5ml trace 2x per week
1/32 teaspoon of equilibrium at WC
20ppm K with 1ml dose 1x per week, rest PPM substitute from equilibrium+sechem nitrogen

I will continue to update if it goes well.


Junior Poster
May 8, 2008
Fifth day after vac+ proper ferts, fishes are ok, but seem BGA is reappearing on the soil again, looks like i havent done a good job in vacuming them....

Do i have to resort to a blackout for 3 days? I have read when bga dies, it becomes more platable for nerite snails, how true is this ?


Prolific Poster
Jan 10, 2009
maybe your substrate is only starting to mineralize and causing your plants stress, causing an imbalance of nutrients in the water column.