Nitrate/Phosphate deficiency

[George Farmer]

This is a copy of a post I put on the Aqua-Botanic forum. Any of you guys have any ideas?

I have a heavily planted Juwel Rio 125 litre (34 US Gallon) which has been setup for almost two years. The plants cover almost 100% of the the substrate and approx. third of them are fast-growers. It is stocked to medium capacity with a community of 2 Angels, 15 Cardinals, 5 Otos, 2 Zebra Loach, 2 Cory julii and 2 True SAEs. Water is pH 6.6 - 6.8, KH 3.5, GH 7. My lighting consists of high-spec T8s (3 x Dennerle Special-Plant, 1 x Hagen Life-Glo, 1 x Arcadia Freshwater Lamp) giving me a total of 99W all with reflectors. CO2 is administered using 2 x Nutrafin units with a DIY recipe giving 20-25 mg/l. My substrate is a fine inert gravel and laterite mix with heater cable. I perform 20% weekly water changes using 50:50 tap/RO and fertilise using Dennerle S7, E15 and V30.

The tank is very healthy with virtually no algae and has until recently shown excellent growth. To boost growth I've tried adding more fertilisers with no success so I measured my nitrates and phosphates both of which were undetectable. I confirmed these results by taking a water sample to my local aquatic shop. Would I be advised to add nitrate to my water and if so what is the best method? Also is there an ideal nitrate/phosphate ratio? Thanks.

 

[Stryker]

You probably have no nitrates because all your plants are stealing the ammonia from the fish away from the nitrogen cycle.

Check your tap water. Maybe if you did a water change using just tap water it would act as a boost to your plants. Mine does as my tap water has around 40ppm of nitrate.

Perhaps another method would be to feed your fish more? Really, I think a more natural aproach here is better and easier to balance.

EDIT: BTW, is that your tank in your sig? it looks excellent!

 

[Silly me]

I use to add about 10mg of KNO3 (salpeter) to my tank every day for three weeks to get my nitrate to 10ppm. now I dont have to do much other than a water change as my tapwater is high in nitrates. but adding PMDD mixed with some extra KNO3 would help aswell..

As for phosphate add some till you get a reading. none means there is nothing for the plant to use 0.1ppm means there is left over for the algae. Personaly I would use the phosphate as the growth limiting factor.. make sure the is enough NO3, K , Fe, etc.. and if your plant look like they need a little boost add some P ( ONLY IF THERE IS NO READING )

I am currenly using growth stick 5:1:5.. it makes for a great fertiliser as long as its planted like root tabs, I had some come lose and float and they did not cause any extra algae growth in my tank but lots of people how had them "leaking" into the water had an algae breakout.. so watchout.

laterite mix causes lots of problems in a planted tank where you dont know what you plants are missing.. adding fertiliser would not really help but should show some improvement, there is most likely a single limiting element short. the most people I know that uses trace element rich substrate has a K potassium deficiency and since potassium is not know to cause a algae breakout it might be a good idea to add a little to see if there is any improvement..

what was the question again, uhm yes.. aliens, seen any?

 

[Ob1]

Hi Silly me

I agree with Stryker, I live in an area where the nitrates are around 10mg/l and the phoshates are at least 5-10mg/l

you could aways over feed the fish that was a joke but I am sure the Angel would not complain

cya ob1

 

[Stryker]

Yep, I'd certainly try methods first of all that don't involve adding it from a bottle as thats just something else to maintain and may knock out other balances your not aware of.

 

[George Farmer]

Thanks for the advice. I think I'll try and get some Pottasium Nitrate and add it slowly over time to see how things go. "Unfortunately" my tap water is low in nitrates but very high in phosphates so I use RowaPhos to limit the Phosphate.

I agree with Silly Me about having the PO4 as the limiting factor, as the infamous Sears - Conlin algae article states.

http/www.thekrib.com/Plants/Fertilizer/sears-conlin.html

 

[Stryker]

Why dont you add it to 1 litre of water, get that to the level you want then add that to your tank. That way you'll be working with higher values so your nitrate test kit will be more accurate.

Sorry if I'm teaching granny to suck eggs.

 

[George Farmer]

Why dont you add it to 1 litre of water, get that to the level you want then add that to your tank. That way you'll be working with higher values so your nitrate test kit will be more accurate.

Sorry if I'm teaching granny to suck eggs.

Thanks for the idea. I was thinking along the same lines. I'll probably mix a solution in a 10 litre bucket at 60 mg/l Nitrate, when I add the 10 litres to the tank it should give me approx 5 mg/l total. That's the theory anyway. I will probably do it more gradually in case there's too much Potassium causing an algae bloom.

 

[Stryker]

Yeah, sounds good. I'm so envious of you. You may of noticed my thread in the hardware forum about lighting. My tank is 24" deep and I just don't seem to be able to really punch down with the lights to brighten things up. I've got two 38w plant gro tubes and two full spectrum 15w tubes and it still don't look that bright.

What you using?

EDIT: never mind, you state it above. Then again, what are the wattage of your various tubes? it looks like you've nothing above 24w ish? How deep is your tank?

 

[George Farmer]

My tank is 20" deep so it's not that much smaller. Dimensions 32" x 20" x 14"

Lighting -

2 x 24" 18w T8 Dennerle Special-Plant (3000K)
1 x 24" 18w T8 Arcadia Freshwater (7500K)
1 x 24" 20w T8 Hagen Life-Glo (6700K)
1 x 30" 25w T8 Dennerle Special-Plant (3000K)

99 Watts total - approx 3 Watts per Gallon

All with reflectors. 10 hour (5 on 3 off 5 on) photo-period

Only quite recently (4 weeks) I upgraded my lighting from 2 to 3 wpg. The nitrate consumption has obviously increased accordingly. I've just ordered some Potassium Nitrate online at £2.97 for 100 grams including postage. Should last me a while. Here's a quick snap of the tank taken just this minute for your interest. Excuse the dodgy reflection of the TV, I didn't want to disturb my daughter watching her favourite program!!

 

[donkey]

£2.97 for 100 grams thats on the dear side

 

[Stryker]

Yep thats a nice tank. I've got my white lights and grow lights on seperate timers, so I can have a kind of sun rise then sun set type arrangement.

£2.97 isn't that bad, I mean its less than £3, its pretty hard to pay over the odds on something thats less than £3.

 

[George Farmer]

£2.97 for 100 grams thats on the dear side

Elaborate?

 

[donkey]

i pay £6:45 for 500gm .and thats with P+P

 

[George Farmer]

who's that with?