stuart_s said:
thanks for your reply ceg
i have a 180L community tank (juwel) with 2x45watt t5 lighting i do not use co2 as i don't understand how it works ( i think i deed to do some serious homework) and i have not fed the plants since the original dose on replanting
i hope this info will give you something to go on and any help would be very much appreciated
thanks again
papasan.
Hi,
Some fundamental principles of CO2 and it's measurement can be found in the Cookbook section:
http://www.ukaps.org/forum/viewtopic.php?t=467
Sam's excellent guide to using fire extinguishers as a source for CO2 is located in the Tutorial Section:
http://www.ukaps.org/forum/viewtopic.php?t=266
We can recommend some hardware for you such as regulators, bubble counters and diffusers if you wish.
You have basically a 50 USG tank and 90 watts T5 so approximately 2 WPG. For T5 lighting CO2 supplementation is more or less mandatory. If you do not dose NPK in addition to this lighting level the plants essentially starve, become weak and algae attacks. Poorly fed plants leach ammonia into the water column due to breakdown of their cell structure as a result of starvation. Ammonia plus light signals algae to spawn and attack/eat the source of ammonia. This is why algae forms on the plants They have a ready source of ammonia to which they can attach.
Each time you change the water you lower the ammonia concentration level. If you change 50% of your water you reduce the ammonia by 50%. If you wait three weeks the ammonia buildup feeds the algae. As a corrective action I would suggest 2X weekly water changes of at least 50% in the short term.
Each day that goes by without NPK addition weakens the plants more and encourages algae. The nutrients released by fish waste alone cannot supply the required levels of NPK at that lighting level. Additionally the fish waste breaks down into ammonia before being broken down into NPK, further adding to your woes.
If you check this page you'll see a list of available nutrients for sale:
http://www.aquaessentials.co.uk/index.p ... th=145_146
At your lighting level, in addition to CO2 injection you would typically need the following dosing of those powders:
3X weekly 1/2 teaspoon KNO3
3X weekly 1/8 teaspoon KH2PO4
3X weekly 1 1/4 teaspoon MgSO4
2X weekly trace element (Plantamin?)
As bugs rightly pointed out, you can lower the light by about half and this would lower the demand for nutrients. I would suggest that you cut the light until you decide whether you want to inject CO2, do more water changes and physically remove the algae that is present. You might also want to consider adding a carbon source such as Excel or EasyCarbo.
Low light and high light are at opposite ends of the spectrum. High light means high maintenance, high nutrient dosing, high water changes to remove ammonia, and high plant growth. Low light is just the opposite.
Bugs, FYI if you are low tech you want to avoid water changes because any new water that is added disrupts the low CO2 levels (which the plants become accustomed to) and can trigger algae. In a low tech the plants recycle the fish waste so you can get away with as much as a 6 month water change interval! Ammonia is much less of a problem when the lighting is low. A low tech system
uses the ammonia slowly.
In a high tech tank the CO2 levels are very high so the function of the water change is to eliminate ammonia and organic waste because the lighting will trigger algae if the ammonia is present.
Hope this clarifies. Let us know if any of this is fuzzy.
Cheers,