fw:Urgent help needed

One more that bounced.

---forwarded message---->

Date: Wed, 24 May 95 08:45:00 PDT
From: KB Koh <KB_Koh at ccm_ipn.intel.com>
Message-ID: <Tue, 23 May 95 17:58:03 PDT_2 at ccm_hf.intel.com>
To: aquatic-plants at actwin_com
Subject: Urgent help needed!!! PH going downnn....

Hi everybody,

I need urgent help and advised about how to control my PH. It keeps 
going down. I thought it was the drift wood that causing the problem but
turned out to be not. My PH is going down by 0.5 a day. Below is a run
down of events to help in your analysis(?). I add half teaspoon of 
Natrium Bicarbonate last night. Is this the right thing to do? Can I put 
limestone rock in the tank? etc....

Setup: Tank size is 50gal (36" x 18" x 18")
       3 x 20W flo. tube (Triton, Aquarilux, Philips super daylight)
       Fluval 303 (fiber, foam and ceramic ring media)
       Large driftwood and many stones
       River sand as substrate with laterite mixed at bottom 1/3.

Maint: Water change (see water test below)
       Add dechloronator to new water
       Add Tetra Flora Pride to new water (10ml to 20gal of water)

Fish : Started with 4 Black Mollies for break-in (2 lyretail died)
       Add 4 Zebra Danio 2 days later
       Add 1 Flying Fox and 1 baby pleco 3 weeks later

Plant: Started with Limnophila Heterophylla, Hydrocotyle Leucopetala,
       Hygrophila difformis, Echinodorus Bleheri, E. Orisis, Acorus
       gramineus var. pusillus, Rotala Wallichi, other Limnophila sp.,
       1 unidentified water plant and 2 unidentified house plant (They
       are growing very slowly but a lots of roots formed). 

       Removed whole Limnophila Heterophylla as they melt and die 10 
       days later

       Hydrocotyle now are slowly rotting. Leaves become yellowish and 
       transparent, and then swept away by water current.

       Add Bacopa Amplexicaulis, Alternanthera sessilis var. lilacina,
       Ludwigia Repens and Ophiopogon Japonicus 4 weeks later.

Water Test:

       Tap water PH is 7.5

       Initial: PH 6.7, Ammonia 0, Nitrite 0, Nitrate 0
       after 1 week: PH ~6.0, Ammonia 0, Nitrite 0, Nitrate 0
                     15% water change
       after 3 weeks: PH <= 5.0 Ammonia 0, Nitrite 0, Nitrate 5mg/l
                      25% water change
                      PH <= 5.0 on the next day
                      25% water change
                      PH still <= 5.0 on the next day
                      50% water change -> PH 6.5
       after 4 weeks: 30% water change -> PH 6.0, Ammonia 0, Nitrite 0, 
                                          Nitrate 2mg/l
                      PH <= 5.0 on the next day
                      Remove driftwood and change 30% water -> PH 6.5

                      2 days later PH down to 5.5

Thanks a lot. rgds..kbkoh