Hey everybody. Was wanting to get everybodys opinion on whether or not I have enough plants as I am getting what I think is GDA. I have a 55gal, pressurized CO2, cannister filter, and 220W lights. My phosphates are off the charts no matter how many watter changes that I do and NO3 in the 60's. I use AP test kits, I know they are not the best. When I test the tap water Phosphates read 1 degree but when I test the tank water it is off the charts (solid dark blue). The city reports verify 1 degree phosphates. I have even tried starting over with pure RO/DI water with the same result. I have no fish as I did not want to kill any trying to figure out the CO2 thing. I have lots of growth now but still have GDA (I think). The water looks like it has little fibers floating around. I have tried using a Diatom filter and the stuff just comes back the next day. I would appreaciate any help. Here are a couple pics.
Thanks
RD

That is a great deal of lighting for the tank, not enough plants also.
Pack 2-3x that amount and reduce the lighting to 110w till things settle down.
Add some excel in the meantime to beat the algae back also.

The rest is CO2/dosing.

Given your tap, just do 50-70% weekly water changes and add:

1/2 teaspoon GH booster after water change

3x a week:
1/4 teaspoon KNO3(later, 1/2)
1/8 teaspoon PO4
TMG or traces 10mls

That should do it.

The rest is all CO2.

Oncwe ther tank does well, then you have a good handle on CO2, then add the 220w for maybe 3-4 hours in the middle of the day.

No more than 10 hours light per day.

Regards,
Tom Barr

Thanks Tom, Will do and will post results in a couple of weeks. Also do I need to add K2SO4?

RD

Which is it ? Many DI units can actually add Phosphates in the IE process. It depends on the active cation resin used. Stick with R/O if possible. The Phosphate can be removed with a Fluidized filter, and Rowaphos, but you run the risk of removing ALL the Phosphates, and that is even worse IMHO since new growth is either absent or corrupted beyond repair.

Phosphates do not directly effect algae blooms. That is a one size fits all marketing myth, that sells alot of product !!! ...Rant Off !

Yes excess phosphate can "contribute" to algae blooms, but only in the absence of good nutrition, and maintenance. Many algaes and bacteria grow just fine in the absence of Phosphates. Plants on the other hand wither, and eventually die. A robust growth rate of plants will always out compete algae in the long run. HTH. Prof M

You will get plenty if K+ from the Gh booster and the K in from KNO3.

Regards,
Tom Barr

Hey Tom, Thanks for the help. My tank is looking awesome. The water is crystal clear and the plants are growing like crazy. I even have one that keeps flowering. Again thanks for you help.

RD

Out of curiosity, have you kept the lighting at the reduced 110W, or have you bumped it back up to 220W?

Jimbob,
I have kept the lighting at 110W. I tried to up the lighting but it was too much and algea started growing even after uping the CO2.

Wait till the plants fill in more and start by adding 1 hour, then 2, then 4 etc each week and noting changes.

It'll namely be due to CO2, as that is the largest "nutrient" that is used when you increase growth rates, 45% of the plant's dry weight is Carbon and it all comes from CO2.

Regards,
Tom Barr