Concerns with doubling my light

[Da Squid]

I have a 75g heavily planted tank with pressurized CO2 and a Nova extreme fixture with 2 T5 54 watt bulbs. The Plants all grow just fine, I fertilize as needed and keep the nitrates around 10 at any time.

I probably shouldn't mess with a good thing, but I was thinking of adding another of the exact same fixture to the tank. Mostly because I've seen some beautiful pictures of plants full of purple and red plants which I've never been able to achieve w/my current setup.

My questions, can I safely run two fixtures next to each other, or will this create heat and electrical problems? I'd rather not shell out nearly $300 for a quad fixture if I can help it. Also, I know more light means more ferts and trimming, but are there any other consequences I need to know? Could the extra light suddenly create wild algae blooms? I haven't seen algae in over a year and don't want to go through all that drama again

 

[cjldad]

There are a few different ways to do this.. You can start by adding the extra light a little bit at a time so your plants have time to adjust to the extra light little by little. A you know, your fert uptake will increase and with all of these changes algae is going to have a good chance to try to thrive.

I have a nova extreme quad and run only two of the bulbs in my 75g. I believe you can run any number of bulbs on these units. Try to and see if you can run just one bulb in your current unit by just taking out one if the bulbs.. You could then really gradually bring up the light one extra bulb at a time...

 

[Da Squid]

I know I can't run just one bulb in my current fixture. I tried this back before I had a CO2 unit. And the fixture I'm intending to buy is one of the more affordable kinds i've seen on the net so I'm pretty set on purchasing that, if any.

I like the idea of introducing things slowly though. Perhaps if I just run the second set of T5's for only a few hours a day and gradually increase that?

 

[fort384]

I ran 2 double T5HO fixtures on my tank for awhile. If you bump the lights up that much, expect some changes... you will need more fert and have to trim more often. If you keep the ferts balanced, you shouldn't notice a huge increase in algae growth... however, nutrients will bottom out a lot quicker, so you have to stay on top of it.

As for the heat... it can be an issue. I solved it by buying a $5 PC fan at radio shack and wiring it up and leaning it up against the side of the fixtures to flow across them. Just make sure you get an AC fan if you go this route. It helped tremendously...

 

[Da Squid]

Thanks! My tank is in the basement, and while not air conditioned i'm hoping it will still stay relatively cool. I certainly will be building a shelf against the tank which I'll put a fairly powerful fan on. I think I'm going to go through with this. I really like the idea of some color and different plants in the tank, and am excited to begin a more challenging fert schedule. I'll probably go with the EI method for a while till I learn the ropes.

Here are some quick pics taken right after my WC.
Ammonia 0, Nitrate 20, KH 50ppm, PH 6.6.

I'd like to try and have some tall bushy red/purple stem plants take over the backround and left side of the tank. The last pic I tried to catch some algae that I was concerned about. Its small reddish and very hard. It only forms on the vals and amazon swords. Diatomes?

 

[fort384]

very nice looking tank! Sounds like a good plan with the fan. If it is blowing across the fixtures and the surface of the water, it will make a dramatic difference.

Check out rotala macranda... it sounds like with your plan you would be able to keep it alive (it is a challenge though!). It is one of the best looking stem plants out there. Here is a pic some I grew awhile back.

I think some HC in the front would look nice too, and you would get it grow very compact with the extra fixture.

 

[BigJim]

Nice tank!

Telanthera Rosefolia is a very nice red plant. I found some nice bunches at a local Petsmart. It couldn't hack it in my med-light 20L, but I'd like to try it again if my LED fixture will support it.

 

[Da Squid]

Thanks! The choices are certainly daunting but I like those suggestions. I think the hardest part will be trying to decide which plants to throw out in order to make room for the red stuff and ground cover.

Any thoughts on that algae in the last pic? It's hardly any trouble at all and doesn't spread, but if I have a fert deficiency then I'd like to get it fixed before my switch.

 

[fort384]

What is your nitrate testing out at? How about phosphates, do you have a test kit for that?

Edit: I see you said 10ppm nitrate, that should be good. Curious on the P, and whether or not you are dosing? How about Potassium and trace?

 

[Da Squid]

Alas I do not have a Phosphate test kit. They arent sold in stores around my area and I kept forgetting to buy one online. You can bet I'll do it before the upgrade though.

My fert schedule will sound a little haphazard, but its worked for me so far. On the macros I dose a little less than a quarter teaspoon of P and K on Mon, Wed, and Fri. On Tues, Thur, and Sat I dose the same amount of a micro blend. Nitrogen I use fairly sparingly as I try not to let my nitrates go over 10. Then every sunday I do a 1/3 WC.
I've never calculated exactly what the carbon content is but I keep my drop checker in the green and have it set to turn on with my lights.

 

[fort384]

What are you dosing? Dry ferts? I would wager if it is dry ferts, there is an imbalance. Dosing the same amounts of KH2PO4 and K2SO4 is not good. Either too much P or not enough K. You want 2 as much K available for uptake as the amount of P you are dosing. I would bet the GSA you see is a result of the imbalance. You want to get that under control before the lighting upgrade.

 

[Da Squid]

Dry ferts it is. Wow, thanks! I wasn't aware about a 2:1 ratio. Since I don't have a Phosphate test yet, I'll just double up on Potassium.

How long do you t hink I should run the new dosing schedule before jumping to more light?

 

[fort384]

That was 20 to 1. You need to read up on dosing. My guess is your po4 is high contributing to GSA. It takes a very very small amount of po4 to hit your target of 0.5-1ppm.

 

[Da Squid]

Just received my phosphate test kit in the mail. Yep, you guessed it, P is off the scale! My plants have shown decent growth for some time now and the fish have always acted very healthy. I'm surprised the dangerously high P levels haven't caused more noticeable repercussions. I've been dosing extra K and will start doing WC's every other day to work on correcting things. I'll need to test my tap water too to see what sort of P i'm working with there. This should be an adventure.

 

[Da Squid]

Follow up question. I'm dosing more K under the presumption that it will help stabilize things and that you can never really overdose on K. But my dry fert is in the form of potassium sulfate. Could the extra sulfates cause any issues?

 

[fort384]

Adding a bunch of extra k isn't going to help anything.

I would just do a big 50% pwc now and another tomorrow and get back to a reset point. You need to use EI or PPS Pro to help you figure out how much you should be dosing. Target dosing is fine too but there still needs to be some measurement involved. Me personally, I would rather have not quite enough of a macro than a huge excess of one.

 

[Da Squid]

Thanks again Fort. I'm slowly whittling my phosphates down and have been actively reading up on the PPS method which sounds like my style (more for aquascaping ease than fast growth).

It still sounds strange to me that WC's don't have to be mandatory! Also, that this fert system can support so many different kinds of tanks. One would think that the recommended dosage per 10 gallons of water would be significantly greater for a high light setup than for a medium. I know I'm not understanding it completely yet, but it makes for good lunch break reading in the meantime

 

[fort384]

I think a lot of the info out there is a little over simplified (not that that is a bad thing), though I do like PPS PRO. I have found adjustments do have to be made to get your formula just right, because there are variables... lighting, substrate, bioload, photoperiod, types and numbers of plants, co2 injection, etc etc.