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Is there a need for Fertilizer when you have high light and co2?

7K views 38 replies 15 participants last post by  saeisbest 
#1 ·
Hi, I'm new to this forum and the 'professional' planted tank hobby. This may seem like a noob question so bare with me. I have a 10 gallon with a Seachem Fluorite and Eco-complete substrate mix. I currently have a 14 watt light but I am planning to upgrade to at least a 20 watt light very soon. I will be dosing API liquid co2 daily. The plants that are in my my tank are listed in the following-

Anubias nana
Anubias barteri
Java Fern
Windelov Java fern
Crypts
Pearl weed (Hemianthus micranthemoides)
American val
marimo moss balls

Is it an absolute necessity to add fertilizer to the tank. I'm only 14 and money is limited.
 
#2 ·
First the Crypts are likely the common Petco Crypts ?
They are Crypt Wendtii which will get when fully mature about 7-9" tall and 6-8" around. So I'd just get one.
Quite a bit for a 10g tank. The Pearl weed will likely give you a hard time/w 14W as if
I'm not mistaken the 18" T8 bulbs are so one of those isn't really enough for Pearl weed.
If you can find someone who will give you a tablespoon full of the beads from a bottle of Osmocote Plus Indoor & Outdoor fertilizer and place one bead under the Crypt and then use two only of the beads to drop into the tank in a place where you can see them
and that the current will flow on them that will fertilize this tank for you for all of the plants except that I don't think it will be enough for the vals cause they grow to fast. So get just one Crypt and eliminate the vals and that would be good ferts for this tank.
The color of those beads is a greenish/yellowish color but when they run out they are translucent. They are not made to be used under water. But they are great for using under the substrate in tanks. So on the package they say good for up to 6 months,
but under water you don't know just how long they will last. So watch for them to turn
to that translucent looking color. The ones you put where you can see of course.
 
#3 ·
No its not absolutely essential to fertilize the tank. There's definitely going to be a difference in growth, and a well dosed tank will last longer. That all being said you could try flourish excel once week, for a cheap and easy fertilization. For a 10 gallon tank a 500ml bottle should last well over a year, and I think the go for around $10 on amazon.
 
#14 ·
Yes I am confused. I guess I mistyped out of habit. I meant to say Seachem flourish. Ive used it sparingly on low tech tanks with good results.
 
#5 ·
If you are on a budget, API liquid carbon is the most expensive item in your line up. Ditch it for this tank.

I have a 4 gallon tank. I dose nothing but fertilize with Osmocote as Raymond says. I put some in the substrate then a bead or two on top the substrate so it can get into the water column.
Stock cheap LED light that came with the tank,,,narrow leaf Java fern and tenellus growing very well.

You don't need all the fancy stuff to have a nice tank, you just have to pay attention to the limitations of the setup and match the plants to it. In your example, you are combing two plants on opposite ends of the spectrum. Java fern can grow in near darkness and you about can't kill it with a stick. Pearl weed is on the opposite end of that.

So you have a choice, setup for the most demanding plant, high light, CO2, ferts, etc.
or
setup for the least demanding and stick with plants that fit that category.
Like all things in life,,,,you can't have your cake and eat it too!
 
#6 ·
Fish food has a reasonable amount of most fertilizers, so if there will be fish in the tank, and you will be feeding the fish, then you would need very little fertilizer. Fish food is low in potassium and iron. If you just supplement these 2 I think the plants will do much better for your.

Keep the liquid carbon, and add a source of potassium and iron. Look into Leaf Zone, and look at Seachem Flourish Potassium and Seachem Flourish Iron. Compare the suggested dosing if you bought one bottle of Leaf Zone OR one bottle of each of the seachem products.
 
#7 ·
Shouldn't the seachem fluorite and the eco-complete be enough iron for the plants. They both have high amounts of it and wouldn't dosing with leaf zone be too much?

Bump: Im worried about the osmocote fertilizer though. I've heard many people not burying deep enough and it made their ammonia go above 8 ppm and their nitrates above 200 ppm. My substrate isn't that deep.
 
#11 ·
It's not all bad, eco complete looks good and provides the plants with a very good medium to root in. It doesn't have any nutrients, but it does have a high CEC due to its porosity. In other words it does a good job of holding onto nutrients introduced by outside sources. Stick with the eco complete, but do so knowing you will have to dose fertilizers in one form or another. Good luck!

Sent from my SM-G386T using Tapatalk
 
#12 ·
To match your budget - just substitute Metricide 14 for the API liquid co2 when you need to order more - it would be cheaper.

Don't upgrade your light if the present one is doing what you like - the higher light may lead to undesirable results.

You may consider dosing a little potassium - Flourish Potassium as suggested by Diana - but do keep off the mixed fertilisers like "osmocote" unless you would like to make life more complicated for yourself. The potassium is needed only to balance the nutrients supplied to plants indirectly by the fish food.

I would also suggest not to add any iron fertilisers for the time being. If ever you see any signs of iron deficiency you may use Flourish Iron for correction - I don't think at your rate of plant growth you will ever need to do that.

Most problems are caused by overdose of unbalanced fertilisers - ie by overdoing things.
 
#15 · (Edited)
Look up Estimative Index and PPS Pro fertilization. All you'll need to buy is KNO3 , KH2PO4 and trace mix (Rexolin APN, CSM+B etc) powders. That's all you need to fertilise adequately. Powders are usually dirt cheap. You'll have 1-2yrs supply for pocket change.

It's as easy as a science experiment in the lab at school.

You can make these into solutions that are much more concentrated than Seachem etc. Most of what you pay for with Seachem is packaging and water with some fertilizer.

If your tank is heavily planted and you stay low tech, I recommend a 1/3 EI dose to start with. Monitor algae and plant growth and adapt. Simple.

Bump: Here's a link to EI

http://www.barrreport.com/forum/bar...tive-index-of-dosing-or-no-need-for-test-kits
 
#16 ·
Well I don't consider my tank low tech anymore. 30 watt light on a 10 gallon that's the max amount of light right? How much fertilizer should I add with these lights and the daily dose of co2?

By the way it's cyber monday. Does anybody know if there are any websites with great deals on plants? Or perhaps equipment?
 
#17 ·
It's still a low tech, just has a fair bit of light. You'll need to be diligent with adding liquid carbon to avoid CO2 deficiency which leads to algae.

If adding liquid carbon plant nutrient uptake increase so ferts need to increase too.

How much ferts depends. It'll be trial and error. As I said, 1/3 EI dose is a good starting point.
 
#19 ·
I added a betta yesterday. I plan on getting pygmy cories. Also how many hours should I leave the light on? I've seen many professional aquascapers leaving their lights from 8 - 12 hours. Would algae be a problem? My tank is soon going to be crowded with plants as some people say that a large plant mass will keep it away. There is a very small bio-load in the tank. Would the pymy cories make up for the Nitrates? It's kind of weird, it's the first time I've been wanting Nitrates in my tanks.

Ammonia-0ppm
Nitrite-0ppm
Nitrate-5ppm
pH-6.8
 
#21 ·
Fish food is indirect fertilisers - both macro and micro. The fish food is balanced nutrition for fishes - it lacks sufficient potassium for plants.

Once you have a lot of plants you may have to balance the fish-food fertiliser for your plants by dosing K2SO4.

Having low amounts of fertiliser is no problem other than slow plant growth - which is not a bad thing. Imbalanced fertiliser is a problem as it causes your plants to show deficiency symptoms. Potassium deficiency, for example, shows up as black spots and holes in older leaf.

High lights and slow growing small mass of plants may create a situation where there is a lot of unutilised plant nutrient available for algae to grow (this is undesirable result of high light). So it is better to have low lights till you have increased the plant mass in your tank.

I would suggest you have a 3 hour light period in the first part of the morning and again 3 hour light period in the evening while waiting for your plants to arrive. Breaking up the light period is an advantage as algae take a longer time to start photosynthesis. Reducing the period of light to total 6 hours also helps as you have higher lights now.

If you keep up this 3+3 light period even while your newly arrived plants were settling down to your tank - you will be rewarded by keeping the algae away. When your fertilisers are at a lower level, your plants do not need longer hours of light.
 
#20 ·
You're right to ask for a nitrate reading first before going EI. I'd always recommend doing so. If N is already high and you dose EI (even at 1/3 dose) you'd end up with more N than you'd likely need. Once you hit N @ 40ppm+ fish can begin to suffer.

Great that your nitrates seem to be at the lower end.

You can also buy K2SO4 powder if you want to dose potassium separately. When you think about it, given the advice above you may get away with only dosing potassium if you like which would make DIY ferts much easier to begin with.
 
#22 ·
Can't I do a 6 hour period all together? I have school. I leave at 7 and come back at 3. The K2SO4 is a dry fertilizer right? Is this good: [Ebay Link Removed] Aquatics Dry Fertilizer Potassium Sulfate K2SO4 1lb | eBay[/url]

if so how long will it last me? Dosage?
 
#23 · (Edited)
You can do a 6hr photoperiod all together. It's no big deal if you can't do 3+3. It's one way to prevent algae, not completely necessary for an algae free tank.

You can also buy timers that turn your lights on and off automatically. They're pretty cheap, some can be expensive though. You can program them to turn off and on several times per day. Example:

Amazon.com: outlet timer


Yes K2SO4 is a dry fertilizer. 1lb will be plenty. Should last you a long time. Hard to estimate, but I would say 1 year plus.

Is there anyway you could get a pic of your tank so we can gauge how heavily planted it is? That helps to guide fert dosing.
 
#24 ·
Just reduce the photo period to 6 till you can manage the 3+3 routine - yes a timer does help in keeping light routines.

K2SO4 is a dry fertiliser and it is also available from the sponsors of this forum, compare prices before you procure.

As you will be dosing only for balancing the fish food, you will need very minor amounts for weekly dosing and 1lb might last several years. If you keep it dry - it does not get bad and has infinite shelf life.
 
#27 ·
Hello someone must be careful with fertilisation from fishes.

It works well with a low light tank or with a little plant mass, where the plants take the nutrients slowly.

However with a certain plant mass, and when the light becomes intense, let's say medium-high light. The fertilisation from fishes is often not enough. Even more true with CO2 injection (co2, not Excel, or easy-carbo). Someone must carefully check the plant's grow and health, signs of algae, etc.

Michel.
 
#31 · (Edited)
Here is my canned response on how to make planted tanks work:

Basically here's my understanding of how this crap works:

In order to run higher levels of light you need to have plants that can make use of all that energy. This depends firstly on the selection of plants you have (for example a tank full of rotala is capable or using more of this energy than a tank of java fern) and how many of the plants you have in the tank (density) AND how healthy they are (dying plants aren't going to use much energy).

You can maximize the amount of light energy plants use by not limiting them in other areas. This means supply ample CO2 and ferts as well. Of course there is still a ceiling of how much light energy plants can use. It's not like if you add CO2 and ferts you can blast infinite light and expect things to be balanced. For this fact I say that you need all the factors I posted before to 'handle' running higher light.

Of course if you keep light as the limiting factor having CO2 and ferts certainly won't harm anything - this has been proven (within reason - you can't ultra-overdose ferts and expect not to run into SOME problems). But once you start ramping up the light past a point plants will begin to use up more carbon, N, P, K, micro nutrients, etc to facilitate the growth they wish to achieve given the amount of light you hit them with. If they are unable to do this you will probably see deficiencies in the plant (unhealthy signs) and algae will likely start to show itself.

The reasons algae shows up in this scenario are:

plants aren't healthy. healthy plants magically keep algae at bay. they just do. There is science behind this but I don't look into this crap that hard.
too much light means that SOMETHING can use it (algae takes advantage)

Basically you need your plants to out-compete the algae all the time for the amount of light energy you are supplying your tank with. Which they can.

Of course algae can still show up also if your tank is dirty, water quality is poor, etc but with good maintenance the above is generally true from what I have experienced

A lot of people get ultra-scientific about the hobby and claim all kinds of facts about everything. IMO this is looking into it too far. It's more of an art / feeling out over experience what works and what doesn't. So don't quote me on the science in this post lol - just sharing what I have learned over the years / what I feel it takes to be successful with a high tech tank.
In general you need to supply your plants with ample CO2 and ferts to use the light you hit them with. If you have high light they will need ample CO2 and ferts or you will get algae. Not dosing ferts will probably lead to your plants encountering deficiencies. So you should absolutely dose ferts in a high tech.

Remember that not dosing enough is WAY WORSE than dosing a bit too much

EDIT:

You have a low tech tank. Liquid supplements that add carbon are nowhere near as effective as pressurized CO2 setups. You still need ferts but not nearly as much as you would if you ran a high tech setup. I thought because the topic title said you had CO2 that you had a pressurized setup. You do not need high light / as much ferts with a low tech setup.
 
#32 ·
Light and CO2 will not grow either plants or algae without the fertilisers.

So even if the fertiliser level is low but balanced - you will not have algae if the plants are able to utilise it entirely as CO2 and light is unlimiting.

I cannot logically think any other way - especially how "not dosing enough is WAY WORSE than dosing a bit too much"
 
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