Absolutely right Gillian, plants are an excellent indicator
of a well balanced tank.

Quote from Baensch Aquarium Atlas:-
"Fish can "get by" with 8 to 10 hours of lights while plants need 12 to 14. The longer period of lighting will not harm fish but less will inhibit plant growth. More intense light used for a shorter period of time is not as beneficial as the right amount of light used for the proper time."

I light for 12 hours because that's the requirement for a planted tank - minimum. I keep Tetras and all my plants are varieties of Echinodorus. Tubes now replaced and condensation cover cleaned. What I thought was discolouration due to heat turned out to be very thin brown algae, strange 'cause the tank itself seems to be free of it. Anyway, the tank is now a lot brighter and new plants have been added so i'll see how it progresses.

Hi Marty and welcome, seems a bit obvious but can you not adjust the output on the Sera pumps?

Java fern is excellent. I put a tiny plant in my unilluminated hospital tank and it just grows and grows.

Just a thought - do you think heat discolouration of the plastic cover could be a problem as this would alter the colour temp.. I'll replace the tubes anyway, but could I be wasting my time/money, and where on earth could I buy a replacement cover for the hood?

Hi leegaff/Gillian, thanks for the replies. I use tubes, one Sunglo and one Floraglo and having just found the outers it appears I bought them in January so they are probably due for a change. Although I haven't got an iron test, I would think it should be OK as I use JBL iron balls in the substrata and regularly dose with Florapride. I'm about to add some new plants so I'll change the tubes at the same time.

Anyone know how to tell when a tube needs replacing? My plants have suddenly started to die off, despite CO2,gravel fertilizer and Tropiflora added regularly to the water. I have heard/read somewhere, that the colour temp. alters as the tubes become older. Could this be the problem? I run them for twelve hours a day and they are now about 6/7 months old.

Lack of oxygen in the water is the first thing that comes to mind. Is the water well aerated?

Sorry to hear you've lost a fish. The difference in pH of .2 shouldn't be a problem and your other readings seem OK. What type of fish is it. I have a Cory which swims around fine then suddenly lies on it's side on the bottom in an arched manner, then minutes later it's off swimming again. Been like that for a couple of weeks now.