Jump to content

Balancing lightly planted tank to control algae?


Recommended Posts

Hi everyone,

Just checking in with a request for any thoughts on balancing light and nutrients for our lightly planted tank to control algae.

We have a 16 gallon tank with a handful of "easy" slow growing plants, and a small company of fish and snails.  We've had the tank for about 10 months now.

We've been trying to manage cyanobacteria and a few types of algae (lately green water and some fine, long green hairs) - with a UV sterilizer, Maracyn, cleaning the substrate and plants by hand a few times a week and water changes once weekly - usually 20%, but 40% every fourth week.

We've cut back further in the past month on light to help fight the algae (still 12 hours, but at peak of 30%), and moved from a norm of <5ppm nitrates to a norm of >40ppm nitrates.

We used to fertilize with Easy Green up to 20ppm nitrate, but with nitrates at >40ppm, we've switched to a single round of root tabs (5 or 6) and SeaChem Equilibrium instead of Easy Green.

The tests we have (all API) show pH 7.2, ammonia 0ppm, nitrite 0ppm, nitrate 40ppm, phosphates 1ppm, KH 5 and GH 6.

Any thoughts on what direction to go next?  Should we keep cutting back on light in hopes that the algae will come under control, and increase water changes to deal with the nitrates?  If so, should we target a specific nitrate ppm in our changes?  Should we look to get below 20ppm so we can go back to adding Easy Green?  Any additional tests we should be running to see whether a lack of a specific nutrient could be holding back plant growth that could consume those nitrates and maybe dent the algae?   Should we be aiming for higher KH/GH figures?  Planting more?

The tank is in a room that gets a lot of light in the morning and is often lit at night.  We cover the sides of the tank when its light is off, but a partial exposure on the top lets light in.  Any thoughts on whether we should be more aggressive in blacking out the tank at night while still allowing oxygen exchange?

Thanks!

IMG_6450.jpeg

IMG_6565.png

Link to comment
Share on other sites

I second the floating plants and Easy Carbon - in one aquarium, my nitrates are NEVER above 5ppm even with dosing fertilizer, and I know it's the salvinia minima taking care of most of it because they never stop growing and reproducing! In another, I was having a black beard algae problem that almost killed my java fern and water sprite, I was seeing nitrates around 40ppm. Now that the BBA is under control (not quite gone yet) using spot treatment with Easy Carbon, the plants are starting to take off.

  • Like 3
Link to comment
Share on other sites

It would be helpful to know what plants are in there. Is that a java fern or crypt in the middle?

What substrate is that? It looks like pebbles. 
 

Also what light are you using? It looks like a Fluval Plant 3.0?
 

Making some assumptions I would say that pebble substrate with basically no CEC would mean a lot of the root tab nutrients are leaching into the water column but that also means that if you are dosing just the water column your slow growing root feeders should be getting enough nutrients from that. 
 

Now the big issue i see is your light. You say its on for 12 hours but you really have 5 hours ramp up, 2 hours full, then 5 hours ramp down. Which equates to less than 7 hours full (the times at very low light don't really do much for your plants). Your light program mimics the sun but that is a VERY HIGH light situation. For low light setups the ramping is really to just keep from shocking the fish. 
 

Try a 1hr ramp up then 6hrs full and 1hr ramp down which would equate to roughly 7hrs full. Leave this setting for 2 weeks to a month and keep a close eye on your Moneywort new growth. You already have small new growth which tells me its getting enough light but could use more. So i would definitely use your Moneywort as an indicator as to what your changes have done.
 

I had similar issues balancing light and nutrients but i have an Fluval Aquasky on a 29gallon (A lot less light in a deeper tank). Take one variable at a time starting with light and make it easy on yourself, dont mimic the sun use 1hr ramp up and down times.

  • Like 1
Link to comment
Share on other sites

6 hours ago, TheDukeAnumber1 said:

A few floating plants may help. Since your other plants are getting root tabs some floating plants will help take nutrients out of the water column and compete with the algae.

Or an algicide like Easy Carbon or Seachem Excel may work.

Thanks a lot for these ideas.  I will def look into some floating plants.  I have done some spot treatment with Easy Carbon, but will try doing more.

  • Like 1
Link to comment
Share on other sites

6 hours ago, Maggie said:

I second the floating plants and Easy Carbon - in one aquarium, my nitrates are NEVER above 5ppm even with dosing fertilizer, and I know it's the salvinia minima taking care of most of it because they never stop growing and reproducing! In another, I was having a black beard algae problem that almost killed my java fern and water sprite, I was seeing nitrates around 40ppm. Now that the BBA is under control (not quite gone yet) using spot treatment with Easy Carbon, the plants are starting to take off.

Thanks, Maggie.  All very helpful!  Glad to hear you've had success with BBA.  Have you been removing plants and drying before applying Easy Carbon?  I can pull some of my plants, but not sure what to do with the ones rooted in the substrate.

Link to comment
Share on other sites

3 hours ago, Superjoepez said:

It would be helpful to know what plants are in there. Is that a java fern or crypt in the middle?

What substrate is that? It looks like pebbles. 
 

Also what light are you using? It looks like a Fluval Plant 3.0?
 

Making some assumptions I would say that pebble substrate with basically no CEC would mean a lot of the root tab nutrients are leaching into the water column but that also means that if you are dosing just the water column your slow growing root feeders should be getting enough nutrients from that. 
 

Now the big issue i see is your light. You say its on for 12 hours but you really have 5 hours ramp up, 2 hours full, then 5 hours ramp down. Which equates to less than 7 hours full (the times at very low light don't really do much for your plants). Your light program mimics the sun but that is a VERY HIGH light situation. For low light setups the ramping is really to just keep from shocking the fish. 
 

Try a 1hr ramp up then 6hrs full and 1hr ramp down which would equate to roughly 7hrs full. Leave this setting for 2 weeks to a month and keep a close eye on your Moneywort new growth. You already have small new growth which tells me its getting enough light but could use more. So i would definitely use your Moneywort as an indicator as to what your changes have done.
 

I had similar issues balancing light and nutrients but i have an Fluval Aquasky on a 29gallon (A lot less light in a deeper tank). Take one variable at a time starting with light and make it easy on yourself, dont mimic the sun use 1hr ramp up and down times.

Thanks a lot for your thoughts here.

You are right that the light is a Plant 3.0 and the substrate is pebbles.  They are covered with acrylic paint, FWIW.  The plant in the center is a crypt.  

I've switched the light to 1 hour ramps and the reduced lighting schedule and will keep an eye on the moneywort as you suggest.

Link to comment
Share on other sites

  • 2 months later...

Following up on this old post, just wanted to report that the nitrate and algae situation in this 16 gallon tank has improved significantly (knock wood).  Many thanks to @TheDukeAnumber1, @Maggie and @Superjoepez for all your advice.  Based on all your suggestions, @Irene's videos and other reading, in the last couple months I reprogrammed the light (Plant 3.0), added salvinia minima and expanded my other plants and started using SeaChem Flourish.

I did spot treatment of algae on plants with Easy Carbon and later hydrogen peroxide.  Lost a number of leaves (and tossed some leafless plants) in the process.  A few of the plants responded well, but on the whole I was more successful with pruning / removing blighted plants. 

I saw this video from Green Aqua (https://youtu.be/Rce2_BgGveU) that inspired me to beef up my clean-up crew with amano shrimp and clithon snails.  The shrimp seem to have had the largest impact.  They were under 1/2" each when they arrived, and were bullied for a while by the alpha zebra danio, but they've grown well and are now grazing around the tank.  The Green Aqua video suggests that clithon snails are more effective than (other?) nerites at eating different types of algae, but ours spend most of their time on the tank walls.

IMG_7051.jpeg.31d73edffd61741e66d41e91407a0e41.jpeg

IMG_7056.PNG.683a19428eec0a35ee9600fb7544bd44.PNG

I had the lamp down to 7 hours a day, but expanded to around 8.5 hours once the algae levels dropped.  

Still dealing with some cyanobacteria and green water, but otherwise more concerned with keeping the clean up crew happy.  Now I just need to learn how to take a decent photo.

 

 

  • Like 6
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...