Need advice on lights

[eggz]

Hi Guys,

I'm thinking of upgrading my lights and considering various options. Currently have a 4 x 1.5 x 2 ft tank. (2ft height) with 6 X 36W PLs. Tried some glosso, put it in an area that's completely not blocked, still grows upwards. I got some Rotala wallichii and after a few days the tips are sort of greenish instead of red, its placed in the center of the tank under that piece of safety glass, perhaps that blocks some of the light. Really like growing high light stem plants though.

Here are my options:

1) change all 6 month old AEC tubes to Phillips PL865, except the 1 Osram I just got.

2) Increase to 8 X 36W PL, i.e add another 4ft fixture, I think there is just about enough space in a 1.5ft wide tank?

3) Change to MH, no idea where to get, how much etc. will need to research. My tank sits under a false ceiling so fix-up and wiring won't be a problem. Only problem will be if there is a need for a chiller, which I cannot afford

If I get an MH, my PLs will probably be donated to my office's Marine tank (collegues trying to set up)

Any advice appreciated.


eggz

[jacian]

The 2 problems you faced might not be a result of insufficent light.

1. Glosso. growing upwards - it is more of a nutrients problem than light. I have glosso growing flat with only 2.4 wpg. On another tank, with 4.8 wpg, the plants keep growing upwards.

2. Let your rotala grow till the water surface. If the plants stay green even at water surface, well, it might not be the lights issue.

just my 2 cents

[vinz]

Benetay posted earlier that Nature Aquarium has 55W PL tubes and ballasts. That's an option you can consider.

Another option is to dose 20 to 30 ppm of potassium (K) per week and see the results. K helps photosynthesis. When I started that regime, my plants stopped rushing for the surface and grew with shorter stems between nodes and sideways. Taking your approximate water volume, your tank is almost exactly 3W/G... should be enough together with K.

Are you dosing iron(Fe)? Helps red plants grow red.

[geoffrey]

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On 11/25/2002 2:52:58 PM

The 2 problems you faced might not be a result of insufficent light.

1. Glosso. growing upwards - it is more of a nutrients problem than light. I have glosso growing flat with only 2.4 wpg. On another tank, with 4.8 wpg, the plants keep growing upwards.

2. Let your rotala grow till the water surface. If the plants stay green even at water surface, well, it might not be the lights issue.

just my 2 cents
----------------

I tend to agree with Jacian. Previously, I had 4X36W PL for my 30x18x15in tank and my red plants aren't as red as I wanted them to be. My H. difformis had ovated leaves. Most people would suspect light right away, yours truly here thought so too.

However, ever since I started adding Dennerle A1 on a daily basis, Voila, I saved 72W of energy and my tank is now sustained by 2x36W PL. Redder plants and my H. difformis are shooting pinnate leaves even when shaded by my N. japonica. And best of all, lesser algae!

[eggz]

Thanks for the advice. I will try dosing some K2SO4.

Vinz, question about dosing K, how do you know when your K level has dropped below 20ppm and you need to put more? Since there are no test kits for K rite?

I'm currently only using Dennerle E15 and S7. I might have under dosed E15, haven't checked Fe levels for a while, but apparently, the E15 doesn't register on the Fe test kits.....No idea what's in S7 though.

BTW, I've switched my red plants from Rotala macranda 'FLORIDA' and Myriophyllum mattogrossense to Eusteralis stellata and Rotala wallichii. Got the emersed e.stellata from Teo's on Sat, hope it works out.

The former 2 plants were just growing too quickly, trimming every week was getting damn siong! []

Guess I'll hang on to my lights for a while....


eggz

[vinz]

I just dose 30ppm per week. K at high levels are not known to harm the tank except to block uptake of Magnesium(Mg). Lack of Mg in plants also affect the utilisation of iron(Fe). So I look out for Mg and Fe deficiency in my plants.

Jacian dose K too, I think. I wonder how he handles this issue.

Someone posted that E15 actually contains K, but I don't know what levels are in it. You can always try using Flourish K first to see the effect. If it works then consider K2SO4 for the long term.