I know that PO4 has been proven not to be the sole cause of algae outbreaks. But this comes up a lot on some forums, especially those that dont deal with 'heavily planted' tanks. So I am asking this on behalf of other folks more or less. On a low tech tank, lets say a 55g with a couple swords, java ferns, and some hornwart, with no special attention given to ferts or anything for the plants, and the tank had problems with algae, would a phosphate removing pad be beneficial assuming the phosphates are at least somewhat high? Asked another way, does the 'phosphates dont cause algae' belief only for high-tech tanks?

For example this was quoted from loaches.com, as a response to someone inquiring about high phosphate levels and their removal:

At issue is that something is going to grow if you add light and fish waste.
The management issue is that we have a choice of what will grow.

So..........if you only add a one little old plant to a tank and expect things to do well and add too much light to the rest of the tank, probably not.

Something is going to grow and with lower plant biomass and coverage, it'll be algae. They only want a few plants, they need to reduce the light if they are getting a lot of algae.

Light, then CO2, then nutrients.
PO4 is not a bad method without any plants to limit algae, or low NO3, etc.
It's tough if you have fish etc...........they release it all the time.
Just enough for the algae to get by ..........if you have enough light.

So throttling light down is a good solution.
Of course many cannot or will not do that also..........

Regards,
Tom Barr

Thanks Tom, that makes sense. So basically in a tank with a few plants, although nutrients such as phosphate could promote algae, its the light primarily that sets the foundation. And with too much light it can be possible to inhibit algae by limiting nutrients as much as possible but better to address the light first. Some forums I am on dont deal with plants in the aquaria all that much (goldfish forums, loaches forums, etc.), but topics like this do come up every once in a while.
~Tristan

Well, when they want plants and also want to limit algae, that tends to be where things get iffy. Some add nutrients in pots and cap with sand etc. But........this only works so well, some might be okay with the results, but plants will leach nutrients into the water as will any sediment.

Fish waste might be cycled well in the tank, but it does not take much to supply algae compared to the plants.

Reducing the light is a better solution, but many are not willing to address the light issue nor reduce it either.

You can still add CO2 to lightly planted tank also and help increase the plant's abilty to grow at low light.

I sort of liken the few plants in a tank example to a garden that's been plowed and fertilized, but the garden only plants 10 of the garden and expects the rest of the garden to remain weed free all the time. Then you go in and try and remove all the nutrients from the entire soil to limit the weeds but that affects the crops as well. The weeds are better adapted to lower nutrients and thus stick around while the crop suffers.

Floating plants are better options for such folks, water sprite is easy and can be floated or planted. In general, most sparsely planted tanks have looked poor, often replacing the plants every few weeks/months, whereas packed fully planted tanks fair much better.

They also look much nicer.
I'm not sure why so many fish hobbyists are scared of adding more plants.
I guess when you fail with adding one or two etc, then you think it's hard and do not want to waste your $$ if they all get covered in algae and rot.

They have all seen nicely planted tanks and often are intimidated, so they know they are possible and like them, they just do not know some of the basics.

You can just tell them with more plants= less waste is left around and more plants = less algae, only a few plants= more algae.

Something will grow if they add light, they have a choice as to what that is.............

Regards,
Tom Barr

I think thats a good summation!

As far as why people just try a few plants instead of a full blown setup... I think maybe its the extra cost of the whole co2 setup and the hassle getting stuff that they cant find as easily at the lfs, or perhaps they think growing beautiful plants is really hard. Then again a lot of these folks have things like loaches or goldfish wich make things a bit harder as I am finding out.

They do not need CO2, that's a myth supported/promoted by many to have a fully planted tank.

I helps produce more growth, but it's not required, it does make you do more work though.

They just need to add a good substrate, have a reasonable fish stocking level, no plant eaters, and pack the tank and do a few minor things from there.
They work very well.

Most CO2 folks do well with the non CO2 approach also.
If they try it.

Regards,
Tom Barr

How would you deal with water changes in the non CO2 approach though? As I've learned here that approach usually requires you to not do frequent water changes.

Say you are just JoeSchmoe fish keeper and don't want CO2 and Ferts, but you want plants in your community tank.

What would be the best approach for lighting and plants? I'm wondering if you can use the really easy species like java moss, java fern, anubias, some crypts, watersprite, etc... I'm guessing you would still battle algae since all of those except the watersprite are slow growers. Maybe add some other stem plants?

Reason I ask is because like the original poster said there's alot of people out there who aren't interested in getting heavily involved in the learning curve and hassles of a CO2/fert. approach. But maybe there is still a way for them to do it?

Reason I ask is because the more I read about the shrimp I want to keep, the more hesitant I am about CO2/Ferts. and yet I will still need to do weekly water changes.

I typically just suggest water sprite floating.
The deal with no water changes using non CO2: the plants, if you have the tank packed, remove all the fish waste. As new waste is produced, the plants nab it asap.

So you do not measure much if any NO3/PO4 etc, one might be up, but the other is typically near zero.

You do not need to do water changes if there's no nutrient build up.

I suggest adding a small amount of ferts for a fully planted non CO2 tank about once a week and about 1/10th or less of the EI dosing rates.

This small amount relieves the nutrients stress on the plants and lets them grow better with less competition with eachother.

Fish waste alone can keep most tougher species going pretty well, adding a little bit more allows you to grow most species though.................

The plants do well, slow, but well.
The key is the growth rate.

Why do some plant species fade out and others do well?
The ones that fade are not getting enough nutrients.
They are not as strong as the other hardy species.
Even some hardy species will die off if there's not enough fish waste.

Note, this is for a fully planted non CO2 tank.

Since the light is low and the CO2 is as well, the plants downregulate NO3/PO4 demand etc, they just do not need much since they are limited with these other nutrients/energy source.

So they do not get the deficiency issues like in higher light tanks with CO2.
Even if they do, you have weeks instead of days to respond and add more fish food etc, prune out some of the more aggressive plants etc.

I'd not know any of this unless I first did high light CO2 tanks and then took what I learned there and apoply it and look for things with this method.

The method and uptake is so slow.............and levels are also low, that is makes predicting things harder unless you know what to look for and have a general idea.

It also makes the method have a great deal of wiggle room in your routine.
Potted plants work well if you have to have them in a tank, but they generally serve no useful purpose other than rotting lettuce if you do not allow them to grow well, they slowly turn brown and rot after 6-8 weeks till you replace them again. May as well use Water sprite and be far more successful and get some utility out of the plants.

Regards,
Tom Barr

Do you mean that's the only recommended plant for a non CO2/Fert tank with water changes?


But usually a light bioload is recommended for this situation right? That's why I figured I won't be able to get away with the very infrequent water changes.

I would like my shrimp breeding tank to also be a successfull planted tank. If it's just not possible, then I will have to postpone the planted tank for a later date.

I was just thinking I could make it work with the hardiest varieties of plants. Maybe I can do a moss garden or something.

Thanks for your continued help Tom.

Thoughts anyone?