brokefoot

Virc003 & Michael,

Were your spiral CF's mounted horizontally or vertically?

brokefoot

Is this a 4' bulb hanging 1' over both ends of the tank?

Virc003

Both of our spiral CF's are mounted vertically.

Here is the fixture I use.
http://www.officemax.com/office-furn...ct-prod3300097

Michael

No, it is a 24" fixture.

niko

So an outdoor pond's PAR value is 800 at the substrate (at 2' water depth). How can I have a tank that is so brightly lit at the substrate? How much light do I need? Can I keep it clean and algae-free?

Let's look at Michael's 40 gallon tank (36" x 15" x 16" tall). It's not 2' tall but it is about 3/4 of that. So I will need a PAR reading of 600 to simulate an outdoor pond's 800 PAR hitting the bottom.

And here are the (amusing) numbers:

Michael's tank with 2 light fixtures on top (70 watts of light) receives 97 PAR:
"@ substrate: Measurements with both fixtures: w/ glass 83, w/o glass 97"

So 70 watts = 97 PAR at the substrate.
=> To get 600 PAR to the substrate we will need 6.2 times the light he has now.
6.2 x 70 watts = 433 watts!

No fluoresent bulbs can be crammed on top of a 40 gallon tank to add up 433 watts of light. There isn't enough room. You will need a 400 watt Metal Halide. Now imagine - a 16" tall tank with a huge, hot, 400 watt Metal Halide on top. Right... You are better off just placing the tank outside, under the open sun.

And here's my usual attack at popular half-baked approaches; I want to see a 40 galon tank with 433 watts of light use EI or PPS. In other words - "How do EI and PPS relate to Nature?". Since they are such great and so popular approaches they should let you take care of such a Natural tank, right? Of course not. Needless to say there will be ultra-fast plant growth (4" a day not uncommon with stems), deficiencies developing overnight, and insane work to keep up with this speed demon of a tank in some resemblance of a balance.

Or... You can emulate the outdoor pond:
1. Rich substrate
2. Good flow
3. Water void of nutrients

Game over. If you care to think, that is.

Funny thing, if you go on one of Australian planted tank forums and look for the pictures of the guy that has an outdoor aquarium plant growing facility you will see exactly that: Sun blasting the super clear water, good flow, and tons of super healthy plants... Ah yes, almost forgot - and MUD on the bottom. That's it. How novel.

--Nikolay

Michael

Niko, quick correction--the 40 gallon you describe belongs to Virc003, not me. I've been making a few minor changes to my 40, and will post PAR results soon.

I hope everyone is as excited about the club owning a PAR meter as I am. For the first time, we can actually measure light levels, instead of guessing based on wattage, charts, traditional advice, etc. We are all in for some big surprises, and will learn some big lessons.

To Niko's observations on natural light in a pond vs. artificial light in aquaria, I will add another surprise. I've posted PAR info for my 10 gallon--the one that has 60 PAR with just a cheap spiral CF. As an experiment, I put that same fixture on my 40 gallon. Now this tank normally has a dual tube T5 NO Coralife fixture (the brand I love to hate) on it, and it gives about 30-35 PAR at the substrate.

The cheap desk light with the cheap SCF in it gave 60 PAR in the 40 gallon too! So why are we paying $100s for special aquarium fixtures when we can get twice the light for $10 worth of stuff from the hardware store?

niko

Because in this hobby it's a habit to not ask simple questions and go with the flow.

I see that Luis Navarro will be coming to speak on one of the club's meetings. He used to have a 30 gallon cube tank with a 250 watt Metal Halide on top. It would be interesting to hear how he maintained that tank.

--Nikolay

fishyjoe24

just tested my tank.

par data collection, 10/23/2011.

aquarium size 45 cube (24x18x24)... oceanic.

type of light fixture zoo med 2 bulb t5 h.o.(high output). square reflector both bulbs use the same reflector.

number of bulbs 2 t5 h.o. 24w each bulb so 48w total

age of bulbs 4-5 months old.

other info.
one is a gisemann midday (6,000k) the other is a coralife colormax.

distance from light fixture to substrate is 22 inches. my light fixtures is 2 inches from the top of the tank using the legs that came with it.

the surface par when the sensor being right in the water gave a reading of 71.
at the substrate... the sensor gave me a reading of 22.

comments. I bought the zoomed hoping to have medium light on this tank. it turns out that I only have low light which isn't to bad. the fixture was bought new for 65.00 so it was money well spent.

plants i'm growing are misc- cryptocornye(crypts). , misc anubias, java fern, and some type of hyprophill. the meter was easy to use it reminds me of a engine diagnostics reader. i'm wanting to go to medium- high light. so i have a 4 bulb t5 h.o. light fixture and going to see what the reading are with that.

fishyjoe24

just did another test on my tank.

par data collection, 10/24/2011.

aquarium size 45 cube (24x18x24)... oceanic.

type of light fixture current sundial 4 bulb t5 h.o.(high output). cured single reflector all bulbs use the same reflector.

number of bulbs 4 t5 h.o. 24w each bulb so 96w total

age of bulbs 4-5 months old on 2 of them, and 2 new bulbs just bought yesterday and put in this morning.

other info.
one is a gisemann midday (6,000k) one a coralife colormax(purpleish/pinkish bulb), and the other 2 are new coralife 6,700k.

distance from light fixture to substrate is 22 inches. my light fixtures is on the top of the tank,can't find the legs that came with it.

the surface par using one new coral life 6,700k and the 4-5 month old color max, when the sensor being right in the water gave a reading of 108.
at the substrate... the sensor gave me a reading of 15.

using the other new coral life 6,700k and gisemann 6,000k at the surface was 107, and soil was 20.

now for the kicker and surprize. all 4 bulbs on. (2 new coral life 6,700k, a 4-5 month old coral life colormax, and a 4-5 month old gisemann 6,000k) - surface was bouncing with numbers from 265- 326 then slow down and gave a 312 reading. at the soil it gave a reading of 53.


comments. I bought the current fixture to put over my saltwater tank, but don't need much light, so i have now switch the fixtures around. the zoo med is on the salt, and the current is on the planted.

plants i'm growing are misc- cryptocornye(crypts). , misc anubias, java fern, and some type of hyprophill. the meter was easy to use it reminds me of a engine diagnostics reader. after the reading, i will be switching the plants out and wanting to trade them for stem plants, and harder to grow fore ground plants.

foreverknight

Ok everyone in the following posts i will give you the readings of 5 of my tanks. it turns out on most of the tanks I am growing nothing more than low light plants but as you will see with the results are really intresting. the last tank in the list will be my 75g and it pearls after the lights have been on for 2 hours and those of you that know i seem to be able to grow almost anything in it which is why i was so suprised with the par readings. Well here it goes