T_T Tragic struck..Planted Discus xpert adv needed

[Fry_Slayer]

T_T Tragic struck... Need advice from Experienced Planted Discus tank keeper
This morning i found my 3 inch discus dead in my 3 footer planted tank, tailed up and between the plants. The fella has been with me for the last 6 months and this a considerable blow for me as i was adding improvements to the tank environment for the past few montns.

I am in need of seasoned veteran advice.

Tank spec as follow:

Tank Dimensions (LxWxH): 170liter 3 feet in width
Lighting Intensity(No of Watts) : 90watt-- (got few old lamp here)
Type of Lighting (FL/PL/MH) : FL
No. of Hours your light is on: 10HR
CO2 Injection Rate (bps) : 2 bps at start n gradually subside
Type of CO2 (DIY/Liquid/Tank) : DIY
Method of Injection (e.g. Diffusor/Reactor): Diffusor
Substrate Used : SAND
How Thick is your base fert : NIL
How thick is your gravel : 1in in front. 2in at back
Liquid Fertilizers Used : Sera Liquid fert, azoo trace minerals
Frequency of fertilization : ONCE PER WEEK
Tank Temperature : 27C~29C
Type of Filter (overhead/internal/canister) : INTERNAL
Filter media used : ERM....PLASTIC SPONGE?
How long has your tank been set up : 7 months

Chemical Properties (Fill what you can)
---------------------------------------

Carbonate Hardness (kh): 3kh
Total Hardness (gH): Unknown
PH : 6.5 - 7 ph
(that is the range in the Serra tester, how did u ppl get reading of 6.8??)
NH4 (ppm): Unknown
NO2 (ppm): Unknown
NO3 (ppm): Unknown
PO4 (ppm): Unknown
Fe (ppm): Unknown

Bioload (Your Fish and Plants)
------------------------------
Fish
2 discus (1 dead now), 10+tetras, 2 sucker fish, 4 flying fox(?), dozen of Shrimps

Plants
medium size Anubias Nana(on wood) x4-5, Anubias Bateri Medium x1 and misc....generally the tank is very well planted with plants covering the whole back of the tank

ADDITIONAL INFO:
>Water chg 30%++ per week, occasionally add water due to fast evoparation rate

>Water is untreated from tap, but went through one external filter and one buffulo inhouse filter, other small fishes shows no ill effect

>was battling BBA a few weeks before, things got under control after i did a minor black out, start changing water weekly (was 2weekly), intorduce DIY CO2 and got a fan to lower temperature, is doing this for about a month now

>when trying out for the rite DIY CO2 i almost CO2 poison my tank a few times, now using air stone when light is off, also the internal filter head is rise above water to agitate the surface

>My tank is feed with red worms and some additional fish food twice a day

QUESTIONS
1) Most of the time i found my discus completely darken in colour when i switch on the light in the middle of the night (in their sleep). If you leave the light longer and they get awaken slowly they change back to their usual hue, but sometime they also can remain in the darken form for reasons unknown to me.is this normal?

2)Lately i found some bubbles like stuff forming and they gather around my rotala(?) leaveswhich reach the water surface, certainly these are not air bubbles...any idea what this mean?

3)Any recommended way of testing O2 suffiency? I read most test kits r some wat inaccurate in this or am i to be corrected in this info?

4)when trying out for the rite DIY CO2 setting i almost CO2 poison my tank a few times, now (before fish dead) using air stone when light is off, also the internal filter head is rise above water to agitate the surface, is there still chance of CO2 poisoning since DIY cant be turn off at night?

5) In my point of view CO2 poisoning (just change yeast the night before so CO2 at MAX) and water quality is suspected to be the cause of death to the fish, any other possible cause?


TQ for reading n replies

[prec]

QUESTIONS
1) Most of the time i found my discus completely darken in colour when i switch on the light in the middle of the night (in their sleep). If you leave the light longer and they get awaken slowly they change back to their usual hue, but sometime they also can remain in the darken form for reasons unknown to me.is this normal?

Ans: IMO, you should not have switched on the lights while in the middle of the night as this is cause them to be stress and in addition, fishes do need considerable amt of dark hours to rest, etc. fishes normally lose their colors while the lights are off. same goes for cardinals, etc. Get your fishes use to a ROUTINE lighting hours and not on and off at any time for ur viewing pleasure..

2)Lately i found some bubbles like stuff forming and they gather around my rotala(?) leaveswhich reach the water surface, certainly these are not air bubbles...any idea what this mean?

Ans: i think they sound like O2 bubbles to me.

3)Any recommended way of testing O2 suffiency? I read most test kits r some wat inaccurate in this or am i to be corrected in this info?

Ans: it is best to first correct ur co2 problem first. 3ft tanks are best suited for a pressurized co2 with solenoid so as to prevent a large pH swing. but as according to you of using a air stone, i think the O2 level should be fine. Try planting more densely.

4)when trying out for the rite DIY CO2 setting i almost CO2 poison my tank a few times, now (before fish dead) using air stone when light is off, also the internal filter head is rise above water to agitate the surface, is there still chance of CO2 poisoning since DIY cant be turn off at night?

Ans: you should try an error for the compositions in ur DIY CO2 bottle to prevent such happenings. creating surface movement will enhance oxygen as well as co2 exchange btw the atmosphere.

5) In my point of view CO2 poisoning (just change yeast the night before so CO2 at MAX) and water quality is suspected to be the cause of death to the fish, any other possible cause?

Ans: Stress. Can be in the form of ur infrequent switching on and off of lights. Internal parasites can be another source.

[Fry_Slayer]

Thanks

For clearification on question 1 & 5
The switching lights in the middle of the night is not a frequent practice, last time when i almost kill my fish by CO2 poisoning it leaves me a bad impression of my fish being lying on the tank floor when i cant see them.

So sometimes i do a quick on n off of lights to make sure they r fine. On rare occasions i do maintainance in the middle of the night with lights on because got no time at day

[mordrake]

you need to give more descriptions on your discus like any external wounds, stomach swell, etc etc.
also discus is sensitive to high nitrate. you need to measure this too.

some sucker fish like to suck the slime coat of the discus.
not sure whether flying foxes like to do it too.

[Fry_Slayer]

I found the fish dead when i was going to work so i did not take a very close look at it (was late to work), partly because i was sad also , but the fish sure was not swelling in the stomach.

About the nitrate level, the sera test kit is a bit unreliable as mention and comfirmed here in this forum by someone else, anyway they have gone through my 2 weekly water chg period, now is once weekly and tank is more densely planted... well i dont know, but the dead fish was used to be bullied by the survived fish, bugger would charged at the deseased on and off when bad mood come.

And yeah, there used to be a senior SAE who likes to suck at their coat but was moved to a other tank during a "maintenance stuff" shuffle