plants stopped growing

[grobered]

After initial success, (my swords were propigating and everything else was growing at a fantastic rate) I now have the opposite problem, plants are dying and swords look terrible and are stunted. I have a 55 gal tank with eco complete, pressure co2, eheim cannister, 160 watts of lighting for 11 hrs a day. I use the EI 3x a week and add about 1 teaspoon of epsom salts each time I add ferts. I also use Seachems Flourish and Flourish Iron on the off days. I do about a 40 to 50 per cent water change once a week. These are the same perameters I was using when the plants were growing great.

I recently borrowed a Hagen test kit and have the following measurements;
kH 5.6 degrees
pH 7 ,Ca 20 mg/L, NO2 0.2 mg/L, NO3 50 mg/L, PO4 5 mg/L

Any suggestions would be appreciated.

grobered

 

[VaughnH]

Re: plants stopped growing

If your KH is 5.6 degrees and pH is 7, you are probably very low on CO2. And, when you say you are following the EI method, what are you dosing in tsp or grams of KH2PO4 and KNO3? It looks to me like your plants are just starving. Please don't rely upon what your nitrate and phosphate test kits tell you, because those kits are rarely accurate unless you very carefully calibrate them.

 

[quenton]

Re: plants stopped growing

I do not get you kh of 5.6 -- no aquarium test kit I know of will give you other than 5 or 6, and even those are pretty iffy, so if you get a 5 or 6, it could be 4 to 7. Which of course if one of the problems with aquarium test kits -- they give you gross ideas only. The ph test is likely +/- 0.2 at best.

Having said that, it sounds like your CO2 is low -- and to ask the same question the previous poster did -- what are the details of our ferts?

 

[Tom Barr]

Re: plants stopped growing

CO2 has the grestest influence on plant growth.
If things suddenly slow down etc, and you are dosing EI based on the teaspoon, then the nutrientsa re covered.

So all that is left is CO2.

Even without knowing the pH/KH, I can still say this: you need more CO2.

Or Excel perhaps in the 55 gal tank, a 4 liter jug is about 38$, so that will last ahwile, up to you there with this amount of lighting.

Regards,
Tom Barr

 

[grobered]

Re: plants stopped growing

Thanks guys for your input, I have cranked up the co2 and will watch for improvement. Responding to your questions, I use the recomendations for a 40- 60 gallon tank; 1/2 tsp potassium nitrate, 1/8 tsp potassium phosphate, and 1/8 tsp potassium sulfate. I also add one tsp magnesium sulfate. I do this three times a week and on the off days add 5ml of Flourish Iron and 5 ml Flourish.

Tom, how is Excel better than Flourish?

Finally the test kit has a multiplier that gives me a value of 5.6 degrees. I am not a big water testing guy to begin with and only tested because I thought it my help solve my problem if the water chemistry was known.

Thanks again.

grobered

 

[quenton]

Re: plants stopped growing

Thanks guys for your input, I have cranked up the co2 and will watch for improvement. Responding to your questions, I use the recomendations for a 40- 60 gallon tank; 1/2 tsp potassium nitrate, 1/8 tsp potassium phosphate, and 1/8 tsp potassium sulfate. I also add one tsp magnesium sulfate. I do this three times a week and on the off days add 5ml of Flourish Iron and 5 ml Flourish.

Tom, how is Excel better than Flourish?

Finally the test kit has a multiplier that gives me a value of 5.6 degrees. I am not a big water testing guy to begin with and only tested because I thought it my help solve my problem if the water chemistry was known.

Thanks again.

grobered

Hm -- I' not tom -- but "Excel" is basically a carbon additive which is supposed to work like CO2. In some situations it works reasonbly, in others it can create problems (annubias is not happy with a full excel dose for example). I think tom was suggesting that if you cannot increase your co2, you might add excel along with the CO2. I add excel along with DIY CO2 in my 65g tank, not sure why -- I just do it.

I don't think I would recommend excel in place of co2, but perhaps in addition if needed.

Excel is not related to any ferts like flourish or flourish trace or TMG.