[Grah the great]

Hi everyone! I have read repeatedly that planted tanks need to be kept lightly stocked to avoid algae problems. How lightly stocked are we talking? Maybe half the stocking level of a fish only tank? I was going to do 40% weekly WC's. Thanks

 

[NapTeamCaptain]

Hi,
I really hope I don't come off as condescending while writing this. I dont know how well you're familiar with planted aquariums and such, so im gonna err on the side of not as familiar and speak from my own experience.

In my opinion, I dont think you need to limit your stock that much. I've had several heavily stocked tanks that were also heavily planted. Your algae is dependent on your water quality, light, how well your actual plants are established, and of course nutrients.

I've noticed that when I did fewer water changes, the algae did grow more than when I did more water changes. But a 40%? Thats a lot. Just stick to 20% weekly and you'll be better than good. Just don't run into the mistake of thinking you can do rare water changes cause the tank has so much plant matter that it's almost a self sustaining ecosystem. I did a 50% water change after like a couple months of not, and that caused a huge and sudden fluctuation of the co2 levels (I dont use co2, but there's always co2 in a tank, thats how plants build mass) which lead to an outbreak of staghorn algae. Luckily, i caught onto it really early, and was able to get rid of it pretty easily.

Light comes in tandem with nutrients. If you have like 12+ hours of light, you're dosing with fertilizer, and you feed a lot, you're likely gonna have algae problems. Dial back on the light, and a bit on the ferts and food. Generically speaking, 12 hours is the maximum amount of might hours per day. I had a 20 gal long with 12 hour lights, and I dosed every 4 days. After a few weeks, I noticed the plants were doing phenomenal, but the algae was starting to grow faster too. So I changed to dosing 1x a week and fed the fish a little bit less and the algae stopped growing so fast.

Plant establishment. When you first plant your tanks, your plants don't start growing immediately. They have to deal with the trauma of being uprooted, moved/shipped, and then replanted. And especially if they're slow growing plants, then it will take some time. And since they're not using those nutrients, the algae will. Once your plants get situated and start growing, the algae will have less food. I suggest sticking in some fast growing plants to help deal with excess nutrients. I like stalk plants cause you can just cut them into ½ or ⅓, plant the pieces, and boom, more plants. They seem to rebound faster. I've had great experience with Ludwigia Repens.

Now as for stocking, I have 2 points to make. #1) the number of your fish doesn't determine your waste production. Its how much you feed your fish. Your fish can't poop/pee what you dont feed them. 10 fish will produce nearly the same amount of waste as 30 fish, if you feed them the same. If anything, i think the 10 will produce more, cause the 30 will actually use the food, while the 10 won't be able to and some of it will just pass through their bodies.
#2) get some tank cleaners. Snails, they love to eat algae. You can get the fancier big ones like Nerites, mystery snails, ramshorn snails, or even rabbit snails; or you can get the regular small "pest" snails (i dont know their name) that many aquarists think they need to avoid. They're really helpful, people just think they look unsightly. I think they make an aquarium look more natural. They won't hurt your plants, they'll just breed to the amount of food available for them. So they eat your algae, and if the algae growth rate slows, then these snails will just die off to the new level of food. They won't harm your plants, only help. You could also get shrimp. Amanos are bigger, but red cherry shrimp will breed a lot so you'll get a whole colony which is cool. Just make sure to provide plenty of hiding spaces. You could get algae eating fish. I haven't had much experience with rubber lip plecos, but my research tells me that they eat algae life long so you don't have worry about them out growing. I do looove me some Otocinclus fish. They're an algae eating catfish. And they're specialty is eating the algae specifically off of your plant leaves so they'll work great at keeping plants algae free.


Hope this helps.

Sent from my SM-A215U1 using Tapatalk

 

[Grah the great]

Hi,
I really hope I don't come off as condescending while writing this. I dont know how well you're familiar with planted aquariums and such, so im gonna err on the side of not as familiar and speak from my own experience.

In my opinion, I dont think you need to limit your stock that much. I've had several heavily stocked tanks that were also heavily planted. Your algae is dependent on your water quality, light, how well your actual plants are established, and of course nutrients.

I've noticed that when I did fewer water changes, the algae did grow more than when I did more water changes. But a 40%? Thats a lot. Just stick to 20% weekly and you'll be better than good. Just don't run into the mistake of thinking you can do rare water changes cause the tank has so much plant matter that it's almost a self sustaining ecosystem. I did a 50% water change after like a couple months of not, and that caused a huge and sudden fluctuation of the co2 levels (I dont use co2, but there's always co2 in a tank, thats how plants build mass) which lead to an outbreak of staghorn algae. Luckily, i caught onto it really early, and was able to get rid of it pretty easily.

Light comes in tandem with nutrients. If you have like 12+ hours of light, you're dosing with fertilizer, and you feed a lot, you're likely gonna have algae problems. Dial back on the light, and a bit on the ferts and food. Generically speaking, 12 hours is the maximum amount of might hours per day. I had a 20 gal long with 12 hour lights, and I dosed every 4 days. After a few weeks, I noticed the plants were doing phenomenal, but the algae was starting to grow faster too. So I changed to dosing 1x a week and fed the fish a little bit less and the algae stopped growing so fast.

Plant establishment. When you first plant your tanks, your plants don't start growing immediately. They have to deal with the trauma of being uprooted, moved/shipped, and then replanted. And especially if they're slow growing plants, then it will take some time. And since they're not using those nutrients, the algae will. Once your plants get situated and start growing, the algae will have less food. I suggest sticking in some fast growing plants to help deal with excess nutrients. I like stalk plants cause you can just cut them into ½ or ⅓, plant the pieces, and boom, more plants. They seem to rebound faster. I've had great experience with Ludwigia Repens.

Now as for stocking, I have 2 points to make. #1) the number of your fish doesn't determine your waste production. Its how much you feed your fish. Your fish can't poop/pee what you dont feed them. 10 fish will produce nearly the same amount of waste as 30 fish, if you feed them the same. If anything, i think the 10 will produce more, cause the 30 will actually use the food, while the 10 won't be able to and some of it will just pass through their bodies.
#2) get some tank cleaners. Snails, they love to eat algae. You can get the fancier big ones like Nerites, mystery snails, ramshorn snails, or even rabbit snails; or you can get the regular small "pest" snails (i dont know their name) that many aquarists think they need to avoid. They're really helpful, people just think they look unsightly. I think they make an aquarium look more natural. They won't hurt your plants, they'll just breed to the amount of food available for them. So they eat your algae, and if the algae growth rate slows, then these snails will just die off to the new level of food. They won't harm your plants, only help. You could also get shrimp. Amanos are bigger, but red cherry shrimp will breed a lot so you'll get a whole colony which is cool. Just make sure to provide plenty of hiding spaces. You could get algae eating fish. I haven't had much experience with rubber lip plecos, but my research tells me that they eat algae life long so you don't have worry about them out growing. I do looove me some Otocinclus fish. They're an algae eating catfish. And they're specialty is eating the algae specifically off of your plant leaves so they'll work great at keeping plants algae free.


Hope this helps.

Sent from my SM-A215U1 using Tapatalk

That didn't sound condescending to me I've had a good deal of experience with keeping and breeding fish and I've had plenty of planted tanks...but very few of those tanks did not get overrun with algae to the point I gave up on them. I am looking into trying them again.

20% would definitely be easier for me than 40%. I had not given thought to the feeding bit...I only learned the other day that most fish only need at most 2.5% of their body weight in food each day, and fish that would be comfortable in the smallish tanks my landlord allows me to have would weigh only a few grams (up to maybe 5-8 grams for a large paradise fish, probably the largest fish I could comfortably house). I can go with snails (I am nervous the shrimp would get eaten, and I've also heard that a lot of shrimp are sensitive to water changes).

I am thinking of trying a walstad-esque lighting period with 4 hours on, 4 off, 4 on each day to try to regenerate the CO2 for the second half of the photoperiod. I was going to use Thrive C as the fertilizer.

 

[ElleDee]

How heavily you stock your tank is up to you, you'll just need to adjust your practices accordingly.

The number of fish in my main display tank has fluctuated a lot this year and when there are more fish I have to do larger WC and vacuum a lot more. When there was only a few fish I needed to make sure my nitrates didn't bottom out. Having more fish is more work on the whole and with less margin for error, but it's doable if that's what you want.

 

[Edward]

Hi
It is all about balance between nitrogen N and phosphorus P suppliers and removals. Suppliers are fish, snails and fertilizer additions. Removals are plants, biological filtration and water changes. In practical terms, if you test for NH4, NO3 and PO4 you will see how well the ecosystem is balanced. Both extremes are bad, without N or P plants will suffer, and with a lot of N or P fish will suffer. Once adjusted, it works well because plants are very flexible in terms of nutrients needs.

 

[NapTeamCaptain]

Hi

It is all about balance between nitrogen N and phosphorus P suppliers and removals. Suppliers are fish, snails and fertilizer additions. Removals are plants, biological filtration and water changes. In practical terms, if you test for NH4, NO3 and PO4 you will see how well the ecosystem is balanced. Both extremes are bad, without N or P plants will suffer, and with a lot of N or P fish will suffer. Once adjusted, it works well because plants are very flexible in terms of nutrients needs.

Aha! Science!

Sent from my SM-A215U1 using Tapatalk

 

[Greggz]

Hi everyone! I have read repeatedly that planted tanks need to be kept lightly stocked to avoid algae problems. How lightly stocked are we talking? Maybe half the stocking level of a fish only tank? I was going to do 40% weekly WC's. Thanks

You can have a very good planted tank with higher fish stocking. But IMO it does require a greater attention to maintenance and providing uber clean conditions.

That means keeping up with filter maintenance, gravel vacs, large regular water changes, removal of any dead decaying plant matter, limited feedings, etc.

And with a well stocked tank, those large water changes become even more important. Most of the best tanks I follow perform at least a 50% water change weekly, and many are more like 70-75%. Trust me both your plants and fish will love large water changes.

As to algae eaters, a well run tank does not need them. I have nothing but Rainbow Fish in my tank. No shrimp, no snails, no plecos, no anything. Many of the so called cleanup crews actually create more waste than they are worth. A well run tank does not need them.

As to algae, it's almost always due to unhappy plants. Provide plants what they need to thrive, and algae is of little issue.

Here's my 120G with about 30 Rainbow fish in it.

 

[Grah the great]

You can have a very good planted tank with higher fish stocking. But IMO it does require a greater attention to maintenance and providing uber clean conditions.

That means keeping up with filter maintenance, gravel vacs, large regular water changes, removal of any dead decaying plant matter, limited feedings, etc.

And with a well stocked tank, those large water changes become even more important. Most of the best tanks I follow perform at least a 50% water change weekly, and many are more like 70-75%. Trust me both your plants and fish will love large water changes.

As to algae eaters, a well run tank does not need them. I have nothing but Rainbow Fish in my tank. No shrimp, no snails, no plecos, no anything. Many of the so called cleanup crews actually create more waste than they are worth. A well run tank does not need them.

As to algae, it's almost always due to unhappy plants. Provide plants what they need to thrive, and algae is of little issue.

Here's my 120G with about 30 Rainbow fish in it.

I wish I could have a tank that looks that good! Since my tank would be a low tech tank sans CO2 injection, should I turn the lights off for the day after the water change to minimize co2 fluctuations caused by the water change? You think a 60% (or 12 gallon) WC on a 20 gallon would cut the mustard?

 

[Asteroid]

I wish I could have a tank that looks that good! Since my tank would be a low tech tank sans CO2 injection, should I turn the lights off for the day after the water change to minimize co2 fluctuations caused by the water change? You think a 60% (or 12 gallon) WC on a 20 gallon would cut the mustard?

I don't think you have to worry about co2 fluctuation if you aren't injecting co2, The co2 will just be low, very low. If your using a potting soil substrate you can get more co2 buildup, but not much.

As far as WCs the more the better as long as your putting ferts back in that might be taken out. Generally I agree with @Greggz that focusing on plant growth is the key to keeping algae away, but if the tank is not heavily planted your goal should be too keep organics low for an algae-free tank in addition to growing plants. That includes WCs, filter cleaning, removing extra food, removing dying leaves and for me using purigen/carbon in the filter. These all are pro-active ways to reducing organics that breakdown and cause algae to develop and work to your benefit in any tank.

 

[Greggz]

I wish I could have a tank that looks that good! Since my tank would be a low tech tank sans CO2 injection, should I turn the lights off for the day after the water change to minimize co2 fluctuations caused by the water change? You think a 60% (or 12 gallon) WC on a 20 gallon would cut the mustard?

Like @Asteroid said, with no CO2 you have little to worry about. When water comes into equilibrium with the atmosphere, it's usually somewhere around +- 4ppm CO2. Despite what you may hear some people say, without injecting CO2 it's not going to get meaningfully higher.

Large water changes are always beneficial. Most times (not all) when you hear someone talking about how they rarely perform water changes, they are the same people who won't show a picture of their tank. Usually there is a reason.

If you follow the most successful people here or elsewhere, water changes are always a part of the routine.

And you can have a fantastic low tech tank. Many of the same principles apply. The "right" amount of light, the right mix of ferts, and attention to detail when it comes to tank husbandry.

 

[Grah the great]

Like @Asteroid said, with no CO2 you have little to worry about. When water comes into equilibrium with the atmosphere, it's usually somewhere around +- 4ppm CO2. Despite what you may hear some people say, without injecting CO2 it's not going to get meaningfully higher.

Large water changes are always beneficial. Most times (not all) when you hear someone talking about how they rarely perform water changes, they are the same people who won't show a picture of their tank. Usually there is a reason.

If you follow the most successful people here or elsewhere, water changes are always a part of the routine.

And you can have a fantastic low tech tank. Many of the same principles apply. The "right" amount of light, the right mix of ferts, and attention to detail when it comes to tank husbandry.

I've heard some claim that tap water tends to have temporarily high CO2 that can cause problems in low tech tanks when large water changes are done. Is that actually the case? I was going to use Thrive C for ferts, likely 4-6 ml a week in a 20 gallon high. I was going to use two household BR30 led bulbs (which are more focused than standard household bulbs - about 120 degree beam angle vs 220-360 degrees) to light the tank (I am not sure how strong they will be but am leaning towards 2,200 lumen bulbs, absent a specific PAR reading) and was going to use a walstad esque lighting regime of 4 hours on, 4 off, 4 on.

 

[Greggz]

I've heard some claim that tap water tends to have temporarily high CO2 that can cause problems in low tech tanks when large water changes are done. Is that actually the case? I was going to use Thrive C for ferts, likely 4-6 ml a week in a 20 gallon high. I was going to use two household BR30 led bulbs (which are more focused than standard household bulbs - about 120 degree beam angle vs 220-360 degrees) to light the tank (I am not sure how strong they will be but am leaning towards 2,200 lumen bulbs, absent a specific PAR reading) and was going to use a walstad esque lighting regime of 4 hours on, 4 off, 4 on.

Some tap water can have CO2 in it. If it does, the only thing you might notice is that plants perk up and are happier for a day or two. Nothing negative will happen from having some CO2 from a water change.

I don't know what 4-6 ml of Thrive C supplies in a 20G tank. Try to start thinking in terms of ppm of what you are adding to your tank. It's the universal language of the hobby.

I've haven't seen any meaningful difference from splitting up a lighting period. I would call it pretty much a myth.

In general, it might be helpful for you to seek out tanks that demonstrate success in a style similar to what you have in mind. And by demonstrate, I mean something that you can see. There are lots of folks perpetuating old myths out there who never show their tank.

The journal section here is great place to start. When you see something you would like to emulate, study their methods. And reach out and ask questions. You will find most everyone here is generous with their time and knowledge.

 

[Grah the great]

Some tap water can have CO2 in it. If it does, the only thing you might notice is that plants perk up and are happier for a day or two. Nothing negative will happen from having some CO2 from a water change.

I don't know what 4-6 ml of Thrive C supplies in a 20G tank. Try to start thinking in terms of ppm of what you are adding to your tank. It's the universal language of the hobby.

I've haven't seen any meaningful difference from splitting up a lighting period. I would call it pretty much a myth.

In general, it might be helpful for you to seek out tanks that demonstrate success in a style similar to what you have in mind. And by demonstrate, I mean something that you can see. There are lots of folks perpetuating old myths out there who never show their tank.

The journal section here is great place to start. When you see something you would like to emulate, study their methods. And reach out and ask questions. You will find most everyone here is generous with their time and knowledge.

I did use ppm in the past and can return to that. I don't know how many ppm the Thrive C adds per ml...I can check if it's on the label. Shall I start with a 6 hour photoperiod and go from there? Good to know that I can perform WC's with near impunity

 

[Asteroid]

...was going to use a walstad esque lighting regime of 4 hours on, 4 off, 4 on.

The split photoperiod is really in Walstad circles known as a "siesta". Walstad thought it was beneficial to give the plants a "time out" so co2 can build back up. This is applicable according to Walstad if you have a potting soil type substrate. Since the soil is heavily laden with organics there is add'l co2 generated. If you have an inert substrate I don't think even Walstad would think there is any real benefit to it.

As @Greggz stated the best way to gain 'real' valuable information is to see a tank you like and find out how it's done. Don't be fooled by scientific conjecture and chest pounding unless you see it utilized in a hobbyist type tank. Usually that would mean one with fish and plants in it.

 

[Greggz]

I did use ppm in the past and can return to that. I don't know how many ppm the Thrive C adds per ml...I can check if it's on the label. Shall I start with a 6 hour photoperiod and go from there? Good to know that I can perform WC's with near impunity

I have no idea of how much PAR those lights you described will produce. You want the light level to be right in relation to your tanks mix of plants and goals.

The biggest mistake most people make with low tech no CO2 is too much light. Without CO2, your goal should be slow and steady growth.

As to hours of light, hard to say. Most people are somewhere around 8 hours, but starting at 6 and working your way up might be a good idea.

 

[NotThePainter]

20% would definitely be easier for me than 40%.

How many gallons is your tank? If it is large, say more than a 40 gallon tank, a 20% water change should be the same amount of work as a 40%. Why? It's because at that point you shouldn't be using buckets.

I've learned this the hard way, BTW. For my 40 gallon shrimp tank I use buckets, because supposedly they don't like big changes. I'll take 9 gallons or so out. (3 buckets about more than halfway full. Any more and my back complains.) But for the 75? That's the hose and powerhead. Dump that into the kitchen sink, then hook it up and add water to the tank. 20% 40% 60%? It just more time for the pump to work, but not more effort.

What I've learned is that water changes need to be easy or you won't do them. And its taken me 20 years to learn this.

 

[Grah the great]

How many gallons is your tank? If it is large, say more than a 40 gallon tank, a 20% water change should be the same amount of work as a 40%. Why? It's because at that point you shouldn't be using buckets.

I've learned this the hard way, BTW. For my 40 gallon shrimp tank I use buckets, because supposedly they don't like big changes. I'll take 9 gallons or so out. (3 buckets about more than halfway full. Any more and my back complains.) But for the 75? That's the hose and powerhead. Dump that into the kitchen sink, then hook it up and add water to the tank. 20% 40% 60%? It just more time for the pump to work, but not more effort.

What I've learned is that water changes need to be easy or you won't do them. And its taken me 20 years to learn this.

The tank in question is a 20 high.

 

[Thelongsnail]

There's a bit of a different culture in fishkeeping in the UK, but 40% shouldn't be a problem at all as long as you are fertilising accordingly.

Water changes remove far more than just nitrates; they also help keep bacterial load down, remove hormones, and ensure that you don't fall into issues re: old tank syndrome - i.e they replenish kH. I do 50-60% water changes on my low-stocked, medium-planted tank with no issues - in fact, it looks better for it!

The only likely reason for people encountering issues when performing large water changes is that they haven't done enough in the past; your tank's water chemistry should be as close to the water that you're adding as possible, barring ferts etc. of course.

 

[-Sutekh]

I've heard some claim that tap water tends to have temporarily high CO2 that can cause problems in low tech tanks when large water changes are done. Is that actually the case? I was going to use Thrive C for ferts, likely 4-6 ml a week in a 20 gallon high. I was going to use two household BR30 led bulbs (which are more focused than standard household bulbs - about 120 degree beam angle vs 220-360 degrees) to light the tank (I am not sure how strong they will be but am leaning towards 2,200 lumen bulbs, absent a specific PAR reading) and was going to use a walstad esque lighting regime of 4 hours on, 4 off, 4 on.

Another consideration I'd like to throw in here... before selecting a fertilizer such as Thrive C, you should really measure your Nitrate and really see how your tank responds to your stocking. I have a non-co2 tank that actually needs regular Thrive because it does a dang too good of a job eating my nitrogen up overtime if I'm not careful. And from my perspective, I felt like there was a good amount of fish in there before I felt it would appear too crowded. Just because you have a low tech tank doesn't necessarily mean you should go with Thrive C.

All about that balance some were mentioning on this thread. Best to measure and then find a solution to a problem than to try to proactively solve a problem you don't know about.