Low Nitrates

[smithrc]

OK folks... quick summery of my planted setup

40 UK gal.
around 200W lighting (2 dennarle bulbs 1 whiter, all with reflectors)
Preasurised CO2 - KH 9deg PH 7 (ish) = Co2 25(ish)
Sand and laterite sub-substrate - with small grave substrate.
Root tabs and ferts as/when.
very little surface movement.

(Previous thread)

now the plants in the other tanks are still going strong, but the main tank is not doing so well...

I had a brain wave. Water changes happen very rarely in our main tank as the nitrate levels dont shift from 0.

When we do water changes - things look up for a bit.

Could all the problems be because of a lake of nitrates in the water (low stock level and hige plant level?

 

[iggy01]

Low nitrates could be your problem! A level of 5 - 10 mg/l is usually the suggested level for a planted tank.

Check the nitrates in your tap water......if that is at 0mg/l also, you may need to dose KNo3 ( potassium nitrate ) to bring it up to the required level. If you do have enough nitrate in your tap water, then more frequent water changes may help.

Good luck!

 

[smithrc]

Right - just too see if this is the problem - I am going to be doing a number of water changes this week...

After a 20% change last night the plants were pearling like mad (rather than a small ammount before.

I'm hopeing it was because of the new nutrients in there.

I'll be doing the same tomorrow too. Hopefully there will be a noticable difference this time next week.

Any other ideas folks?

 

[George Farmer]

How heavily planted and what fish stocking level are you ? Apart from lack of growth are they any signs of nutrient deficiencies i.e. browning/yellowing of leaves, black spots etc.? I have to add KNO3 every week, my Dennerle ferts provide everthing else.

 

[smithrc]

leaves are yellowing and then browning then being eaten by Mr Plec

The tank isn't very heavily planted... as they arnt not growing... i'd say 1/4 of the tank has plants in the substrate. there are 3 amazon swords in one spot, valsallis (sp) has spread a lot too and now has the back 2 corners. With a large clump of java (the wiggly one) on a bit of bog wood... (i could get a piccy but the camera is packed)

stocking is quite low,

8 phantom tetras
3 danios
4 small clown loaches
one 10" common plec
10ish shrimp.

 

[Yenko]

That's a problem; I have a 10 gallon tank suffering from nutrient deficiency, despite it containing 10 guppies and a 2.5" goldfish that I'm overwintering. Unfortunately, the only place in town I can get KNO3 is the local hydroponics store, which caters primarily to "tomato" growers.

 

[smithrc]

I did a 25% water change mid week and the plants are looking greener...

Unfortunatly All our tanks are just about to be de-commissioned and moved to my parents while we move house.

If they thrive on neglect - they are in luck over the next few weeks - I'm removing the CO2, wont be adding ferts, the lights will be on timers still.
Oh and there are going to be added filters to keep them all going as the other tank inbabitants are homed in the 4ft.

they will have all the nitrates they want for a couple of weeks!

 

[jhd]

It happened to me too, the same thing with leafs getting yellow. When I added fert tablets in the substrate, it helped a lot. Apparently, some plants develop large root system and depend on nutrients from the roots, not only leaves. Fert added to the water does not provide that, I was told.

 

[Jen]

Possibly a stupid question here... if you do water changes, wouldnt that make the nitrates even lower?

 

[Yenko]

Some municipal water has 10-20 mg/l of nitrates in it, but also supplies lots of trace elements. Between water changes and fish food, you can provide everything the plants need, but perhaps not in sufficient quantities to provide for plants in a high light high CO2 setup.

 

[Pescado Guy]

Yeah i would definatly add some KNO3... www.gregwatson.com is an INCREDIBLE place to buy KNO3 and other fertilizers. Oh and i would also check your potassium; you might have a definciency there too.

Kevin