Inufficient CO2 or too much light?

[anarchy]

1)May I know if 1 bps using reactor with 144W for my 4 ft by 2 ft by 2ft is too much or too little? The pH is 7 and kH is 4-5.

2)For high-lighting plants, is 216W enough or too much for a 4 by 2 by 2 ft tank?

3)If I use 216W for a 4 by 2 by 2 ft tank, how many bubbles per second is enough? Using solenoid and reacotr. pH is 7 and kH is 4-5. Plants are high-lighting plants like stellata, ammania gracillis.

[PeterGwee]

1)Your CO2 is too low. Drop the pH down to 6.6-6.7 for a KH of 4 and 6.7-6.8 for a KH of 5. Make sure you keep the pH within the range when the lights are on using only CO2. The rest is just nutrients....

2)I always fall back on the W/G rule which neven seem to fail me..but it does seems that larger tanks don't need that much light. 216W is about fine but 144W is simply too low. You can grow about almost all plants at 2W/G...the key is keeping the CO2 high so that plants would be more efficient in using the amount of light given to them.

3)Bubbles per second is a rough estimate for a start. You need to measure the pH and KH to determine how much CO2 you have in there. Note that circulation plays a vital role in large tanks as the water mass is larger and lag times longer. You would need to make sure that the CO2 system is up and responsive to plant demands during the day when CO2 uptake is the greatest. Failing to do so would result in loads of problems especially if you give them loads of light.

Regards
Peter Gwee

[anarchy]

Thanks a lot my friend. Now I kno why my tank got so much algae. looks like one bubble per second with solenoid is too low.