I have a 110g tank with 6 t5ho's 54w and co2 w/controller and reactor,uv light,eheim 2028. I had just redid my tank with soil master select for my substrate 3 months ago and cycle went ok , Now i have been fighting BGA , my PH is 6.7 and the end of each week i have to add baking soda to keep my KH at 4.0, I have tested my KNO3 at 0 so i add some to raise it to 5.-10. my PO4 reads at 3. witch i did not add any at all , I did replace 2 t5 for some 10K {my t5 are over a year old ad i would like to get 1 more 10K and 3 6700K}. Does it take some time before these nutrients do get absorb into the substrate or am i doing this all wrong, I don't have a lot of plants to began with and i do need to get a lot more in, Can i just throw in some floating plants to get by, What kind of readings should i have and do i need to add anything else, I have been doing water changes every week to keep the BGA down!! need help

You probably have blue green algae because your water is too low in nitrates. And, with only a few plants in the tank it will be hard to avoid algae in any case, especially with 3 watts per gallon of T5 lights. You fertilize for the plants to use the fertilizers, not to build up what is in the substrate.

You can add a lot of floating plants and help reduce algae problems by shading the tank and by the plants absorbing the tiny bits of ammonia that are generated by the fish, by rotting food and plant debris.

I suggest that you forget about testing the water for nutrients for now, and just follow the EI fertilizing method as closely as you can, plus adding a lot more plants, floating or otherwise.

In addition to Vaughn's response you may want to look at the following:

1. Duration of light. How many hours per day are they on?

2. Can you raise them in some way? This will help reduce the INTENSITY and slow growth a bit.

3. Amazon sword plants can get big quickly so they can help shade things.

4. Get some fast growing stem plants at first, then replace with what you want, when the tank is settled and working/looking as you want it.

Hope this helps.

Thanks guys , My lights are on for 10hr all 6 t5's , Should i just use my 2 new 10K's for now and run them for 8hr or should i run 4 lights until i get a lot more plants, Now what kind of plants are fast growing ? Are the plants they sell like in Pet Smart and PetCo fast growing plants , I think some are not even for aquarium use they just throw them in water tank

Hi,


try 6 to 9 for a bit until you get things under control, then go back to 10.


I would go for just 4 of the bulbs, your choice which ones. May as well use the 2 10k you have.......You want to be closer to 1.5 or 2 wpg at first. You can always add later.

Many stem plants will be fast growing.

Some species to look at that you can research and are very available in most places:

Ludwigia
Rotala
Hygrophila
Bacopa

Hope this helps.