MH or T5 for HC?

PMD

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Okay, I have a standard size 125G (72 X 18 X 21) with the following:

Parameters:
EI fert routine,
CO2 injection with two external reactors plumbed
in-line,
Two Eheim 2217 filters,
Two Aquaclear 110's for additional circulation,
Aquasoil,
585 watts of Coralife Aqualight PC lights (3 watts per
gallon for 8 hours per day and 4.5 watts per gallon
for a three hour noon burst)

Problem:
1. The HC refuses to grow and is actually dying.
The other plants grow well and HC is the only one that
does not respond to the light and fert routine.

Possible solutions:
I am thinking of replacing the PC lights with stronger lights.
Possibilities include the following:

1. Coralife Aqualight Pro 72" which includes three 150
watt metal halides and 4 96 watt PC's for a total of
834 watts.

2. Nova Extreme Pro 72" which includes 12 39 watt T5
lamps for a total of 468 watts. This fixture has semi
individual reflectors.

I am not interested in hanging the fixture and each of these
fixtures have legs that will raise the fixture a couple of inches
over the water.

My questions are as follows:
1. Does anybody have experience with either of these two
fixtures?

2. I know the first fixture will emit adequate light for HC.
Will the water overheat from the metal halide lights
raised just a couple of inches over the water?

Will I have to raise metal halide lights 8 or 12 inches to
prevent overheating? How about if I place the lights
over a covered aquarium using just the legs? Will the glass or water overheat?

I anticipate that the metal halide lights would be on 1 to
3 hours per day depending upon the plants' response.

3. Does the second fixture have adequate PAR for HC in a
125G tank? I know that T5 lamps are very cool so the
heat issue is nonexistent with those lights.

4. Any other light fixtures that might be appropriate for a
125?

Thanks for any and all input.

Regards,

PMD
 

VaughnH

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Before changing the lights, which seem adequate to me, I would work on your CO2 system. HC needs CO2. Do you use a drop checker, filled with 4 dKH distilled or deionized water, to measure how much CO2 is in the water? If not, that should be your first step. Once you verify that you really do have about 30 ppm of CO2 in the water, and the water circulation is taking that CO2 enriched water to all parts of the tank, then would be the time to look at better lighting. That's just my opinion, of course.
 

PMD

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MH or T5 for HC?

Hoppy,

I appreciate your opinion!

I do use a drop checker, filled with 5 dKH distilled water.

My reading are consistently green to yellow with 5 dKH water.

I believe that the CO2 is circulating to all parts of the tank.

Total gallons turned over per hour is over 1000 gallons.

Regards,

PMD
 

Gerryd

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Hi,


2. I know the first fixture will emit adequate light for HC.
Will the water overheat from the metal halide lights
raised just a couple of inches over the water?

It will certainly be warmer. I would not recommend placing the lights that close to the water. My unit (HQI Current Sunpod) has a built in fan that helps in this regard and keeps the ballasts cooler.

Will I have to raise metal halide lights 8 or 12 inches to
prevent overheating? How about if I place the lights
over a covered aquarium using just the legs? Will the glass or water overheat?

YES. I would not place your lights that close with just the legs. You will burn the plants. I have a 180 and have a 3x150w 6500 mh fixture and it is now almost 18" above the water. I am full EI and this height seems to be good. I was at 12" for a long time and that was too much.

4. Any other light fixtures that might be appropriate for a
125?

Yes, I have the Current sunpod and outer orbit and they both work well. Good light, quiet operation, built in fan.

I think as Vaughn states, you have plenty of light, you just need to get your ferts right. How long has the tank been setup and cycled?

Also, note that pump ratings are for 0 head height. I doubt you are getting the circulation you think you are. SOmething else to keep in mind.

Try placing the DC in different places to see if it goes green or yellow everywhere.

Yellow is not good for fish, so you may want to back off a bit.

Hope this helps.
 

PMD

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Gerry,

Thanks for the information.

How long do you run your MH lights daily?

The tank has been cycled for sixs months and all other plants in the tank ( more than 20 varieties) pearl very well.

I don't see any indication that the ferts or circulation is out of order.

The Aquaclears are at zero height since they sit on the back of tank. They are rated at over 400 gallons per hour each.

The pearling by the other plants is telling me that there is plenty of CO2 in the tank.

The HC has an occasional pearling bubble, but it is very mild. The HC is shrinking and at the present rate will probably be dead within a few weeks.

Perhaps someone has experience with growing HC in a 21 inch depth with PC lights. What was the wattage used?

Regards,

PMD
 

ceg4048

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PMD;25751 said:
Perhaps someone has experience with growing HC in a 21 inch depth with PC lights. What was the wattage used?

Hi,
Yes. Here is an example of HC growing on the foreground of a 150 USGallon under T5 compact fluorescents with reflectors. The distance from the substrate to water line is 24 inches. Total wattage distributed across the canopy is 495 watts.


I agree with Gerry and hoppy. Deterioration of HC is strictly due to poor CO2 at the substrate level. Additionally, your assumption that other plants are pearling are indicative of adequate CO2 is not quite valid. Firstly, not all plants have the same carbon fixation efficiency and secondly CO2 distribution in the tank is never homogeneous. the substrate is the worst location for CO2 as the gas tends to rise away from the substrate to escape the tank. It is therefore necessary to direct CO2 in the direction of the substrate in deep tanks. My solution was to direct the return flow of high powered filters through long sections of spraybars mounted on the back glass. The flow is then directed towards the front and then is deflected down towards the substrate. This was combined with high CO2 injection rates from two separate external inline diffusers.

In my opinion you would best be served by upgrading your filtration, reworking the flow and increasing the injection rate to compensate. Introducing higher lighting would simply increase the CO2 and nutrient uptake demand and would get you in more trouble, not less. The Eheim model you noted is barely able to deliver 125 GPH when filled with media on it's best day. Large tanks suffer more than others due to stagnant areas so you need to spread the distribution of the powerheads or filter output along it's length.

As I reworked flow distribution in this tank the HC grew to the point where it actually became annoying. The pearling was so excessive that large mats of it would float up out of the substrate. I've since replaced it with different carpet plants.



Cheers,
 

PMD

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Ok, I hear what you guys are saying.

The CO2 is currently directed towards the upper 1/3 of the tank via the two spray bars.

I'll rework the flow and see how it works out.

Thanks to all who responded to my questions.

BTW - What fixture did you use ceg4048?

Brand etc.

Regards,

PMD
 

ceg4048

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Hi PMD,
I'm in the UK so I used the ASL Lighting Units that have the metal "gull wing" reflectors => The Coral Garden - ASL T5 Compact Lighting Units

This is a not-that-well-known system which is an alternative to the much more popular Arcadia/Interpet systems over here. The reflectors are wide but not tall so they fit easily under the canopy. The separate twin ballast can also operate their bulbs independently which the Arcadia cannot so this was a better deal.:cool:

Cheers,
 

PMD

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Hello ceg4048,

Thanks for your input and the link.

Beautiful tank BTW!

Regards,

PMD
 

Gerryd

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How long do you run your MH lights daily?

Right now about 10 hrs per day. This is the ONLY light I am using. No additional tubes of any type.

Also, currently 20" ABOVE the surface, so now close to 4' to the Riccia at the bottom........

Flow is huge in planted tanks. Also remember that growth will impact this as well. More bio-mass = less flow generally.

Ceg is absolutely correct when he says that bigger tanks need more and that there are more dead spots.

Sometimes my biggest issue is that most folks are NOT dealing with tanks > 75 gals, so I sometime set my benchmarks incorrectly.

Right now I have an 1800 gph for the main sump pump, a Magnum HOT, and an additional Rio 800 pump that provides a substrate level current.

I am STILL playing with flow. I want to see every leaf move, and that is not happening, YET lol.

Good luck and keep us posted.

I agree that Ceg has a lovely tank.......

Ceg,

Could you PM me please with a descr on your dual reactor setup and what you mean by 'high injection rates'?
 

PMD

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QUOTE from Gerryd;
"and an additional Rio 800 pump that provides a substrate level current."


The Rio 800 pump sounds like a great idea.

Did you just place it on the substrate at the back of the tank?

Regards,

PMD
 

Gerryd

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Actually stuck it on the side glass towards the front up about 4 inches off the bottom and hid it behind some Lobelias.

I then used a couple of spare parts to make it like a periscope for the outlet so is not as visible and kind of peeks around the leaves. I can still see it, but bet in a couple of weeks, will be invisible.

Goes right across the front of the tank about 1-2" above the substrate and blows across my Riccia..........

Comes on with the c02 timer :)

I think I may do another smaller one (or two) as I have some areas of thick Ludwigia growth and a lot of driftwood that impedes flow.

I think the extra RIO helps a lot. I can see it causing some wave type action in conjunction with the rest of the flow.

I see that I have about 3-5 spare rios of various sizes laying around, so will see how many I can incorporate.

Only bad thing is that each pump has a power cord.
 

ceg4048

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Hi Guys,
Thanks for the compliment. As I said, an effective alternative to all those extra pumps is to simply use multiple large filters and to plumb their outputs to long lengths of spraybars. Each of my two filters are rated at 1700 LPH but when mounted and filled with media only deliver about 800LPH. If I had to do it again I would use two FX5's which are rated at 3000LPH I believe, or use the Ocean Clear with external pumps.

The thing that most don't realize is that bigger filters with stronger pumps also give you better biological filtration under these high lights. This is a massive advantage in algae control. Pumps by themselves, while they do improve circulation can't add better filtration.

Remember that you are not limited to using only a single spraybar. I now have 5 feet of Fluval spraybars joined by rubber unions mounted across the top of the back glass. The Fluvals spraybars are smoky gray so are more discreet, not like the ugly green of the Eheims. In fact any non-toxic plastic tubes with holes drilled in them can work so we're not limited to "aquarium" plastic tubes.:rolleyes:

This method does require external reactors though so if you are a DIYer and you want to save money you can fabricate and mount a couple of Tom's venturi reactors on the output of each filter.

I haven't tried them all of course, but so far there are few plants beyond my reach using this method in this tank - and there are no ugly pumps to hide...which is NICE...:cool:
2387308170038170470S600x600Q85.jpg



Cheers,
 

PMD

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Fluval spray bars/tubing sound very effective.

PVC pipe could work too, but I hate white tubing. Know of any safe paint to apply to the pipe?

Placement possibilities include placing the tubing an inch or two from the bottom - extended along the entire back of the tank - facing forward. Then add just enough flow so that a gentle current extends to the front of the tank

Maybe use an Eheim 1262 pump for distribution - it's rated at 900 gallons per hour. Too strong?

I could regulate the flow strength by adjusting the diameter of the holes.

Any recommendations on rubber suction cups. The Eheim seem to lose their grip in only a few months.

Regards,

PMD
 

ceg4048

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Hi,
I'm not sure about the paint but I am fairly certain yo can find black or at least gray pipes. I've not tried having the pipes down near the bottom but I noted in Tom's 180 project his outlets from his closed loop system exits down low so as long as the CO2 mixture is exiting from the pipes it should be OK. The 900GPH figure sounds about right to me.:) Remember that you need the CO2 enriched flow to reach the front so it has to be more than just a gentle flow. In my configuration the flow is from top down so I can also tweak the effluent to ripple the surface as needed.

I don't really have difficulties with the rubber cups and Brand X cups are cheap enough that they are easy to replace. The Fluval cups are a bit more flexible so they don't harden as quickly. Might just be luck in my case though.

Cheers,
 

Tom Barr

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The HC I have in the 180 has a lot of current.
I can switch between PC and MH or both.

The plant does best at higher intensity, but high rates of growth may not be be what you really want later.......careful what you wish for......

I have a nice ultra fine mist traveling most of the mat's length from a venturi mazzei valve.

Most nice HC displays are open designs, not dense dutch stem plants which zap the CO2 and light.

ADA does this.
With increased current, you can get away with more however.



Regards,
Tom Barr