PAR at 0.8W/gal- or we really do not need much light

Tom,

I think I have posted a thread or two on this myth since I have seen the light

I am using 1.3 wpg of T8 and providing slightly LESS PAR 20-30 at substrate than you have and so far so good.

Also 1 meter from substrate....

Stauro 049 and downoi are growing steadily but slowly.. I see no difference in the health of the plant from when I used >2.5 wpg of MH....The RATES of growth is all that has changed and is what I wanted...

I doubt I will ever use much more than T8 or T12 from now on with plants....

 

Seems like for most folk two full length T5NO with good reflectors should work for "normal" height tanks. I'm planning to do just that for my planned 75g which is 48x21x18. Currently planning single clipons Miros by Icecap.

Should save electricity and still give manageable growth.

The light choices are definitely heavily weighted toward T5HO however. Not many places carry a variety of spectra in NO.

jim

 

"I see no difference in the health of the plant"
interesting, you should see different growth patterns. According to Dutchy, his Ludwigia became much wider when using 50 mmol instead of >100mmol.
I am thinking of creating my new tank (1.76cm wide) with 6 rows of T5 39w, dimmable off course. With 849mm in length, i can create 3 rows of in total 6 tubes giving me optimal spread. Also, by using 6 tubes i can vary with color on one end of the tank.

However, i am not yet sure if i place them like this:
----- -----
----- -----
----- -----

or:
-----_____
-----_____
-----_____

if you know what i mean. Tank is 70cm deep (27.5")

 

Can't agree more Tom. Still need to get the masses to believe. I still see a lot of Europeans especially those who are producing scape after scape using and suggesting very high lighting.

I myself found out (back in the flouro days. lol) that a single T5HO (0.9WPG) set 2ft above my 125ltrs substrate was still crazy fast growth.

Technology is a problem though. As new things come out they are marketed as the best and promoted heavily, then old technology becomes unfashionable and therefore less used and less choice.

T5HO is the best lighting.....for most users purposes. that being high bay warehouse or office lighting. getting more light into small areas etc. Not for planted tanks though. We should all have stuck with the 'nasty old fat tubes'.

AC

 

You folks are 100% right but, I do not think many ppl will give up on their t5ho lights. Wish I have a par meter and it looks like nobody is going to lend one even if I am willing to pay a deposit for the price of the meter.

 

Gilles,

I said the 'health' of the plant, not the SIZE of the plant. I never said that I did not experience different growth patterns...

I have smaller growth, but well formed, good color, no algae, etc. Growth is steady. I can see new Anubias leaves every other day with the minima. new bolbitus stalks, etc.

I don't necessarily equate large plants with healthy ones...and is all I wanted to point out...

The two can be mutually exclusive

Sorry for any confusion.

 

The only downside there is (for me personally) is that the tank looks very dim at very low light levels, especially at a bright sunny day. I like it a bit brighter, which gives nicer colour to fish and plants. As some of you know my light is around 55 - 60 micromols, which doesn't give me algae problems.

I've encountered ony one plant that gave me trouble so far, Ludwigia Peruensis, which only wanted to grow with higher light. Also plant colouration is less, but it's an easy trade off. Better no algae than a little bit more colouration.

regards,
dutchy

 

Interesting. I was running a 12 watt 6500K Aquagrow 500 led fixture that put out 30 umol at substrate in a 60x30x30cm (11 gallon) tank with pressurized co2. I couldn't get HC to grow, it just withered and died. The hairgrass, wisteria grew quite well but not too fast.
Enter the DIY 12 Cree LED fixture I just built with dimmers. Been using it for two weeks. Now I have 80 umol at substrate. We'll see if the HC grows now. But I'm worried that I just bought myself an algae problem. Other plants are growing like mad.
My question: what PAR is necessary for good HC growth (assuming good CO2 and EI)?
Tnx
Instantcrow

 

Well, you have to ask yourself if you can supply enough CO2 with that kind of light (and wear sunglasses lol) I've grown HC at 60 mmol with no problems.

regards,
dutchy

 

I think some plants require higher lighting and some dont but the majority can be grown in either. They may look different in the different setting but they will grow. For example, I used to have pressurized co2 and higher light on my mini m with s.tropica 49 and it grew much smaller and compact. Not I have it in the the same tank with out EI, Co2 or high light and it just grows taller. The same with Trithuria Sp but the only thing that changes was the lighting intensity. It grows pretty much the same in both cases.

It would be nice to have pics of the different plants in the different settings. Also to see which ones really do require Co2, high light and a strong dosing regimen.

 

bsmith

You make an assumption there that is the light that made the change. You say yourself it used to be highlight, CO2 and ferts, now it is low light no CO2 and no ferts.

Have ruled out that it could well have been the CO2 addition or fert addition that caused the more compact growth? After all the CO2 may well be higher at the substrate level in a CO2 enriched tank and therefore in the non CO2 tank it may be reaching upward more to get more CO2!!!

AC

 

I think its common knowledge that plants stretch to try to get more light.

 

Not 'more' light, but 'other' light. Plants tend to grow compact with more 'blue' light.. AFAIK

 

Not entirely true, as Coley already stated it's also the demand for Co2 what makes the distance between internoides increase. Low Co2 = more distance between noides. Plants try to grow upward and out of the water since the Co2 levels are higher there.

Also when plants have 'enough' light and more than enough nutrients and Co2 they will focus their energy in growth/colour etc. If they have more than enough light and nog enough nutrients they will focus their energy in finding nutrients and/or Co2. As you can see lighting sets the demand for nutrients, with 'low/medium' lightning it's more easy to get the small excess of nutrients hence the reason why plants can still look good with 'low/medium' lightning.

 

Ime, plante with less than optimal co2 grow in a stunted state with frail looking growth. As far as having excess/enough nutriens making them focus on color, anytime I have higher than normal N the red is always lacking.

How about we try to not pick apart our statements.

 

When N is too low many plants will also color more red than with enough N. Dutch aquarists have been using this trick for a while to get extra red plants just before the tanks are being judged. Ofcourse excess nutrients cannot make a plant as red as high lighting would, the effects are more noticable in growth. i.e. more compact plants. I believe Dutchy has an excellent picture showing that effect.