Liquid Fertiliser.

[Jaymz]

Sorry if it's been asked before/frequently, but I was looking for tips on what the best type of liquid/tablet fertiliser is for my plants. I started off without any plants ages ago but have added them over time and recently got a CO2 kit, but have no specific fertilising substrate for my plants, only sand. As such I'd rather not have to put fertiliser beneath this as it'd be a large job. So I was wondering, with my Co2 kit and some liquid/tablet fertiliser, would my plants be ok? And what's the best you can recommend that I could find from my LFS or on the Internet?

Many thanks.

 

[Colin_T]

I use Sera Florena. it is a liquid iron fertiliser for plants and seems to work well. You can also make up or buy laterite balls. These are simply small 10mm diameter clay balls that have been allowed to dry out for a few days. Then they are pushed into the gravel around the base of plants. You can use any sort of red or orange clay. The more red it is the more iron it has in it.

 

[Jaymz]

I had checked out my LFS for Florena having heard of it before, however they don't stock it and nor do any UK-based websites that offer free delivery (Not meaning to sound tight but delivery can be up to five quid from some, and buying more just seems to push the price up) Or do you know of any such UK sites that offer it? (Unlikely I know, given your location)

I might try those Laterite balls, just clay you say?

Many thanks!

 

[Colin_T]

Can’t help you with a UK website, sorry.

Laterite is simply iron rich clay. It is a red or orange colour. Just find some red or orange clay and make little balls out of it. Allow them to dry on a window shelf or table and then put them in the gravel around the plants. the plant roots will grow into them and get the iron that way. You only need one ball for each plant. Swordplants can have a couple.

You can make liquid iron fertiliser. Go to a nursery or garden centre and buy a small box of iron chelate. Add a small amount of this powder to some water and shake it up until the iron chelate has dissolved. Then add a small amount of this solution to the tank each week. You should get an iron test kit to monitor the iron levels in the water so you don't overdose it and kill the fish.

 

[Dave Spencer]

Two questions:

Jaymz - what are your light levels and tank size? This will be the deciding factor on what you will need to dose. If your levels are sufficiently high, then you need a more complete dosing regimen than the trace elements already suggested. If you find that your light/growth levels require NPK dosing, then look at Aqua Essentials for potassium nitrate, potassium phosphate and trace mix (the name of an even cheaper alternative escapes me at the moment). A read of the EI sticky on this forum should make it clear as to what your needs might be.

Colin T - what is the obsession with iron? Light and CO2 are significantly more important considerations, followed by NPK. Iron is an important trace, but it shouldn`t be the only nutrient recommended. Any decent trace mix will cover iron issues without ever coming close to being toxic to your fish.

Iron tests kits we use in the hobby are essentially a waste of time. It is difficult enough to measure in a lab, which I do frequently at my work.

Dave.

 

[Colin_T]

My obsession with iron is because CO2 is readily available from the atmosphere and the fish and filter bacteria. Nitrogen & phosphorus is readily available from fish food and waste. Potassium is for flowering or fruiting and since most aquatic plants don't do either, it isn't high on my list of essentials.
Light is something I expect people to have on the tank anyway so I don't normally bother mentioning it.
However Dave, you are right in the fact that plants need light, CO2, nitrogen, phosphorus & potassium as the main requirements. But since most of those are already in the tank in plentiful supply, I just go to the trace elements and the main one that encourages plant growth is iron.

 

[Dave Spencer]

CO2 and NPK may not be available in the tank in plentiful supply. Most tanks, even lower light, benefit from CO2 injection. At higher light levels, CO2 becomes virtually essential to prevent it from becoming a limiting nutrient, and therefore resulting in algae.

Have a read of the EI sticky and read why NPK are also so important. Try not to be so dismissive of the importance of K, as your statement is incorrect:

http/aob.oxfordjournals.org/cgi/content/full/92/5/627

Co2 injection can increase plant growth by factors up to ten. Iron prevents yellowing of leaves. Increase the light levels and deficiencies in carbon and NPK manifest themselves before, and with worse effects before ay iron deficiency.

Concentrate on light levels first and foremost. This is the engine that decides how fast the tank will grow and what nutrients require dosing. Then look to CO2 and NPK. Dose with a decent trace and forget about iron. Just recommending isn`t sufficient advice and does not address all the plants needs.

Dave.

 

[Jaymz]

Could you remind me how to work out the light level again please? I recall it being something like lux and.. volume or something? Or is it just the wattage you want? (I'm such a noob ) My tank's 96 litres and 81 wide, 31 deep and 46cm tall, but I can't find out my bulb's specifics until tomorrow. (The box is in the garage and is unavailable at the moment)

 

[Jaymz]

Ok I got the box that the bulb came in, it's a 20W, 18,000K rating and 55 Lux T-8 tube. It actually says it's 'designed' to help plants grow better, but I bought it a while ago for the fact it emphasises the colouring of the fish.

 

[Colin_T]

To work out the volume of water in the tank
measure Length x Width x Height in cm
divide by 1000
equals volume in litres

your tank can hold about 110litres but will hold less when you have gravel in.
There is about 4 litres in a gallon, (3.785litres in a US gallon and 4.5litres in a UK gallon).
Therefore your tank holds about 27gallons and with a 20watt light over it you will have a bit less than 1 watt per gallon putting it in the Low light category.

The globe you have is a low wattage globe and won't give you much light for your plants. Basically it is a 20watt globe with a temperature or Kelvin (K) rating of 18,000K, which is a bit high for plants. The globe has lots of blue light in and will make certain ornaments and corals glow.
You really want a globe with a temperature rating between 6,000 & 10,000K
You could use that globe and add another one with a lower Kelvin rating and that would increase the watts per gallon and give the plants a better coloured light.

 

[Jaymz]

The hood of my tank is pretty much designed for only one bulb, so it seems I'd be better off replacing it, unless I try and save up for a new hood.

When it comes to increasing the WPG then, it seems the bulbs I look at increase in length as the wattage goes up, or is it possible to get higher watts in the same size tube? The hood only takes 24" bulbs.

P.S - Also have a reflector, metal/silvery one, if that makes any difference.

 

[Colin_T]

as a general rule the longer the tube, the higher the wattage. There are new fluorescent lights around called T5s and they have a high output (HO) and a low output (standard) range of globes. If you change to a HO T5 light unit with a couple of high output globes you will be able to significantly increase the amount of light over the tank. Otherwise if you stay with the standard fluoros (T8s) then you will be limited to about 20watts per globe for a 2ft long globe.

 

[Jaymz]

So it seems the better option would be a whole new lighting unit? Egh, that'd cut into my savings a bit. I'm planning on getting a new tank in the near future, so maybe it'd be best just to last it out with what I have and wait for a new tank before I sort out all the lighting systems? My hood won't fit a new unit I don't think, and the replacement luminaires are expensive, and would only be unused when I change tank.

 

[Colin_T]

if you'r getting a new tank in the future then just wait and buy a decent light unit for the new tank