Upgrading my 75 gallon tank (need help with lighting)

Hello guys!

I currently have a 75 gallon planted tank with 6 clip on lamp lights equipped with 6500K and 1600 lumens per bulbs (total of 9,600 lumens which is kind of low for a 75g). I do liquid dosing everyday. But after a couple of failures to grow some plants, I decided to upgrade my lights and possibly add a CO2 system (any suggestion would help!).

My budget is around $200 to $500 (leaning towards $400) and has thought of getting two sets of either (48 inches)

Odyssea T5 Quad Timer Aquarium Light Marine FOWLR Cichlid or FLUVAL 3.0 PLANT SPECTRUM or BeamsWork DA FSPEC LED or Finnex Planted+ 24/7

I also have some old lights lying around( Current USA Satellite Freshwater LED 38inch and $100 marsaqua ebay lights) but I am not sure if they are strong enough.

I am planning to have had a carpet plant, Alternanthera Reineckii, Ludwigia, and some other plants (heavy planted tank).

Any thoughts on the lightings that I have listed?

Thanks in advance!

9600 lumens on a 75 gallon works out to be about 33 lumens per liter which is sufficient for growing most plants.
What needs to be taken into account when growing plants in a tank with the depth of a 75 gallon is the PAR at depth. The more water light has to travel through to reach plants the less effective it is. This requires not just lumens but bulbs that have high PAR and PUR ratings.for growing carpeted plants youll need 30 PAR at substrate. Id suggest googling a PAR depth chart or going to rotala butterfly light calculator. Adding CO2 without the proper lighting wont do anything other than grow algae. Make sure you have a comprehensive liquid fert and some root tabs.

utahfish said:

9600 lumens on a 75 gallon works out to be about 33 lumens per liter which is sufficient for growing most plants.
What needs to be taken into account when growing plants in a tank with the depth of a 75 gallon is the PAR at depth. The more water light has to travel through to reach plants the less effective it is. This requires not just lumens but bulbs that have high PAR and PUR ratings.for growing carpeted plants youll need 30 PAR at substrate. Id suggest googling a PAR depth chart or going to rotala butterfly light calculator. Adding CO2 without the proper lighting wont do anything other than grow algae. Make sure you have a comprehensive liquid fert and some root tabs.

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so after using the rotala calculator, I got 121 PAR and I am not if 1 would be good enough. Would 242 PAR be too bright (if i get another set)?

I also calculated my current set up and it showed me 37 PAR, which is considered high enough to grow carpeting plants.



Thanks in advance

samoyed123 said:

so after using the rotala calculator, I got 121 PAR and I am not if 1 would be good enough. Would 242 PAR be too bright (if i get another set)?

I also calculated my current set up and it showed me 37 PAR, which is considered high enough to grow carpeting plants.

View attachment 104832

Thanks in advance

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Sounds like your lights are sufficient. What kind of fertilizer are you using, what kind of substrate do you have?

utahfish said:

Sounds like your lights are sufficient. What kind of fertilizer are you using, what kind of substrate do you have?

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I dose excel flourish everyday and CaribSea Eco Complete. But I am planning to rescape my tank next week and get more susbstrate and possible add fert tabs (its 3 inch deep atm).

samoyed123 said:

I dose excel flourish everyday and CaribSea Eco Complete. But I am planning to rescape my tank next week and get more susbstrate and possible add fert tabs (its 3 inch deep atm).

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Root tabs will go along way especially if you have heavy root feeders like swords or crypts and carpeting plants. I use aquarium concepts root tabs they have a lot higher concentration of nutrients than other commercially available tabs like flourish tabs.

samoyed123 said:

I dose excel flourish everyday and CaribSea Eco Complete. But I am planning to rescape my tank next week and get more susbstrate and possible add fert tabs (its 3 inch deep atm).

Click to expand...

Carib sea eco complete ive used it will go nutrient dead after about a year and will need to be replaced. I just use sand now with root tabs so i dont have to replace the substrate. Those pre packaged substrates work well for a couple months but quickly exhaust their nutritive benefits and just become dead anaerobic substrate.

any suggestions for the light?

Finnex lights are amazing. The fluval is top of the line. I say start with one light and get another if you feel it's necessary. It's more than likely that one light does the trick for you.

Whatever you do, get an LED fixture that you can dim and has rgb that you can control.


Those T5 fixtures are high intensity, insanely bright and consume so much energy.