Yellow water

[CrashCourse]

hi all, would like to seek assistance for this problem. i have noticed that the water in my tank turns brownish yellow, in a matter of 2 days, after water changes (the colour of the water prompts me for a water change). initially, i suspect that it was the tannis from the driftwood but i realised that after removing the wooden ornaments, the problem persists.

is there a reason for this or is this normal (should i continue the regular water changes, get an internal filter or somethin')? the setup was completed about 2 months ago with a 1L CO2 tank running at 1 bps, tank size is 2x1.5x1 ft, a single 2 ft PL light left on for 15 hours and a powerhead to circulate the water.

i also added 20+ cardinal tetras recently. is this a right time? they are doing fine for now, but i hear they are vulnerable to unfavourable water conditions. please advise.

thank you for your time.

[juggler]

Maybe the substrate? What type of gravel or base fertiliser are you using?
Could your lighting be yellowish?
Or maybe your fish food stains the water?

Maybe you can give more details of your the tank by cut-and-paste the tank profile sheet at http://www.aquaticquotient.com/phpbb...pic.php?t=7182

[CrashCourse]

Beginners Info Sheet
++++++++++++++++++

Tank Dimensions (LxWxH): 2x1x1.5ft
Lighting Intensity(No of Watts) : 45watts
Type of Lighting (FL/PL/MH) : FL
No. of Hours your light is on: 15
CO2 Injection Rate (bps) : 0.5 bps
Type of CO2 (DIY/Liquid/Tank) : CO2 cylinder 1L
Method of Injection (e.g. Diffusor/Reactor): diffuser currently, planning to use a reactor
Substrate Used : jebao
How Thick is your base fert : 1.5 - 2inches thick
How thick is your gravel : 1 - 1.5 inches think, dimension: sand 1 - 2mm
Liquid Fertilizers Used : nil
Frequency of fertilization : nil
Tank Temperature : 26c - 28c
Type of Filter (overhead/internal/canister) : only a small power head
Filter media used : nil
How long has your tank been set up : 2 months


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

have not bought any test kits yet, no figures for now

Carbonate Hardness (kh):
Total Hardness (gH):
PH :
NH4 (ppm):
NO2 (ppm):
NO3 (ppm):
PO4 (ppm):
Fe (ppm):

Bioload (Your Fish and Plants)
------------------------------

State what fishes and plants you have to the best of your ability

20 cardinals and a black pleco introduced last week

6 amazon swordplants
1 green cabomba
1 small java fern
3 driftwoods amounting to 2.6 kilos
plus other plants which i have no names of

Describe your problem : as above and i suspect iron deffiency, because red plants turning green

problem description. If you have picture which could help then please post them

i will post pictures asap