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problem with a 10g tank... to much phosphate?

1043 Views 9 Replies 6 Participants Last post by  micheljq
ok so lately i am getting GSA and now BBA is starting to grow...

my tank is low-medium light with co2 injection at 20-30 ppm (co2 drop checker shows a green color some times lime green and some times just a dark green...) co2 is going into a inline reactor to be dissolved. I also does flourish comp. 2x (1ml) a week with PO4 3x (2ml) a week and excel 3x (1ml) a week

so my po4 reading is coming out at 10ppm... now that is extremly high and there are fish in the tank....

so can to much po4 cause algae problem? the only plants i have in the tank are blyxa jap. - Ludwigia sp Red - HM (Pearl Weed)

using a Fluval 304 on this tank and to the inline reactor before it goes back into the tank
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How heavily planted is the tank? Sounds like you're dosing quite a bit of ferts. If you dont have enough plants to use them up then you wind up just feeding algae. Also at low med light may not be enough to drive the plants to utilize that level of fertilization, regardless of co2 levels.

Disclaimer: Im no expert, definitely still learning planted tanks myself. Those are just some ideas that jumped out at me. Hopefully someone else can come along and better diagnose the problem(s). Pics would probably help too.
here is a picture of my tank that is having the issue... this is having the same issue... 40B

i did some test a few mins ago and this is the results

nitrate (not nitrite) - 0 (i heard this is to test the ferts in the tank?)
phosphate - 10+ (the max the comparing sheet can give if not over)

baby tears seems to be doing fine but some other plants like downoi and blyxa jap are not in good shape nor growing as healthy as i would hope too...
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No nitrate, no plant growth. Get the nitrate up to atleast 10 ppm
so in order to get nitrate up, does more fertz (Macro and Micro right?)
You need to pick up some Potassium Nitrate. You can get the SeaChem version, Kent, or just get the dry Potassium Nitrate. Dose enough nitrate to keep the level at 10 to 20 ppm and you should be fine. The nitrate, phosphate, potassium and carbon are used to in unequal number depending on your plants so continue to test regularly or be prepared to go the EI route and do Large weekly water changes.
so in order to get nitrate up, does more fertz (Macro and Micro right?)
Nitrate is a macro nutrient, so is phosphate, potassium and carbon.
micro nutrients are all the rest including iron, copper, manganese and such.
so will dosing flourish comp. bring my nitrate up?
No not really. Comp. has a very minuscule amount of nitrates (0.07%). You need a nitrate source.
Seachem has a liquid source -
KNO3 dry fert will dose N, and some K.

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