The Planted Tank Forum banner

Plant Tank Help (New Member)

1079 Views 25 Replies 11 Participants Last post by  Rex Grigg
Happy New Year to all. I found this site after stepping up my interest in my aquarium.

My background is all science. Cell Biology and Genetic Engineering. Suffice to say the terminology and biological/chemical knowledge is a given. I have been interested in aquaria for 15 years, but only recently got into plant specific aquaria and the cultivation of plants. I only recently moved into a townhouse I actually own, the previous time I was renting, so I suppose that there was always a bit of hesitation to fully commit, especially if forced to move.

But not now. I have a 125 gallon tank (48l x 24w x 24d) that is to me, small. Could be bigger but oh well. I use a single Eheim 2217 filter, one 300 watt heater (the lights add enough) and a 10lb CO2 canister that has 2 bubbles per second. Light is 4 40w Powerglow lights.

I am yearning to get a tank like the Amano ones. I want Riccia to bubble, and the plants to flourish, but it has only been a month and my tank seems worse.

Algae is rampant. If I use one less light, then there seems no photosynthesis. Add one more (for 5) and the plants do better but algae is rampant. I change water (from the tap) once a week 30 gallons. No luck yet. Nothing seems to grow well yet. I am upset some find it so easy when I have all the ingredients but it is not working. Some plants are doing well (Aponegeton Crispus, Anubius sp.) but eventually black fur algae gets to it.

I try to limit the fertilizer hoping to limit the algae, we will see. I am very frustrated to have invested almost $700 into the tank to make it plant specific only to find it makes no difference.

Any encouragement or ideas would be nice. I have not discounted the idea of tearing the entire tank down and starting anew. Maybe bad substrate, but right now, nothing is out of possibility.

Water hardness is good, pH is 6.2, but neither the fish or plants seem bad. I am really trying to get rid of the algae. I am trying to start here first.:frown:

I look forward to many more posts.
See less See more
1 - 20 of 26 Posts
Yes I am. I recently purchased a 10lb canister and have a regulator with solenoid. I am using a bubble ladder and have one or two bubbles per second.

I do get O2 bubbles on the plants, but the algae is bad. Or not getting better and going away. I do water changes and try to use minimal fertilizer, but either the black fur algae gets worse or the green algae forms on the glass.
I think you might need some fast growing plants to out compete the algae your tank might be understocked with plants. Also 160 watts won't grow riccia mainly low light plants and some medium light plants The reason your anubias and aponegeton and having algae issues is because they grow slow. What substrate are you using and fertilizer ?
I am guessnig you need a lot more CO2 then that. I have 2 different diffusors in my 120 gal tank each going at about 2-4 bubbles a second. That puts me at about 30ppm CO2 which is what you are looking for. Ferts are very important. If you have a heavily planted tank with lots of CO2, lights, and ferts the plants WILL outcompete the algae.
For some fast growing plants, I can send you some wisteria or bacopa carolinia if you'd like for just the cost of shipping.
The "Watts per gallon" rule doesn't really apply to large tanks like his.
The "Watts per gallon" rule doesn't really apply to large tanks like his.
oh i thought it was the other way around ?
Bigger tanks definitely need less light per gallon, but you have 1.28 wpg so you're kind of marginal for being medium light. Not a problem depending on your choice of plants. Also, if you don't want algae you CANNOT limit the nutrients! You won't need as much as if you had a high light setup but you DEFINITELY need to ensure the plants don't run out of anything. The most important nutrient that the plants need is CO2 and frankly, 2 bps on a 125 gallon tank seems pretty low. If one of the types of algae you have is BBA (black beard algae), then you don't have enough CO2 getting into the water.

I would recommend checking out this thread for dosing amounts, just do water changes to ensure nothing builds up (plus your fish will thank you for it too).
Consider making/using an inline CO2 reactor to increase your diffusion, plenty of designs on this forum. Do you have any algae eating fish? Algae is tough to keep in check for everyone with a new tank, hang in there. More CO2......DC
Take a few minutes and read my Guide.

But in short:

Limiting nutrients limits plant growth and does nothing to affect algae. So get your dosing regimen working.

Get more CO2 in the tank. At a minimum you need 30 ppm. I can say without hesitation that you are no where near that amount.

Get some fast growing plants in there. A LOT of fast growing plants. If you buy them in bunches then at least 25-30 bunches.

Get more light over the tank. Get rid of the "magic bulbs" and just get some 6500k bulbs. If you don't have reflectors then get some. Personally I would highly recommend that you head over to and get some 55 watt kits. If it were my tank I would get 6 total kits and mount the lights and reflectors running from the front to the back of the canopy.

And $700 in a 120 gallon tank is nothing. You have gotten by cheap so far. The normal range is $10-$15 USD per gallon for low to mid tech and more around $20 USD a gallon for high tech.
See less See more
My advice is to talk to folks who actually keep big tanks like yours. Lots of the so called conventional wisdom breaks down or changes in 90 gallons or more.

People will tell you things they found to be true in a small tank that doesn't hold for bigger tanks.

For instance, you need less nutrients (ppm) in a bigger volume of water than a smaller.
My $700 outlay is in upgrades only. It does not take into account the cost of lights, tank or stand or any heaters/filter. That amount is ONLY what I have added in CO2 system, additional plants and some fish.

Thanks to all for the help. I will tell you this:

Suggesting that I ADD more CO2? My pH during the day is 6.2. Adding more CO2 will make it more acidic and probably kill the fish.

Yes. I have plecos, shrimp and Malaysian snails. No results yet.

Does a pH of 6.2 seem too low? I know gas solubility is pH dependant, and most literature states that the pH during the day should be about 7-7.2 with CO2 usage, and lower at night with its release. To have a low pH in the day tells me something.

I can add more light, but the algae blooms bad. I can add one more 40 watt strip, but I am afraid to see how bad it gets.

Help me back from the brink.....
See less See more
I would appreciate that very much. Personally email me and I will get back to you. Thanks in advance.
Pay no attention to the pH. Look only at the CO2 concentration. pH change due to CO2 injection doesn't harm fish. Without knowing your kH it's impossible to tell you if the pH is too low.

Ignore most literature. Most of it is flat out wrong or extremely outdated.

Again. A planted tank requires balance. You need to balance the plant mass, CO2, nutrients and light.
test your KH and then test your pH and then you can find the amount of CO2 (Rex Grigg has a good KH/pH table on his website). You want around 30 ppm. If the pH is getting too low, then boost the KH. Depending on the fish you have, it may not be an issue though. I have apistos, plecos, tetras and my pH is routinely 5.7 - 5.8 with no problems. Between the Aquasoil substrate, a low KH and pressurized CO2, the pH goes down a lot.

Forgot to mention, some things will muck up the KH/pH table giving you a false CO2 result. To double-check, put some tank water in a cup and do a pH test. Let it sit for at least 24 hours and do another pH test. The difference between the two tests will give you an approximate CO2 amount. A difference of 1.0 equals about 30 ppm and a difference of .5 equals 15ppm. So if the pH tests went from 6.2 to 6.7, then you have about 15 ppm.

By the way, when you say "the algae blooms" do you mean Green Water (water looks like pea soup)?
The algae I have a problem with is black beard algae (it grows on the leaves, mostly the Microsorium) and anything else in the mid to top level of the tank. Green algae grows on the glass and the topmost leaves, and I am suspecting the light is too strong (but I have been told I have too LITTLE light).

I am willing to do what it takes to make this work. I want what you all have and I have the gear to do it.

I admit, a CO2 bubble ladder is not the best, I will look into a better diffuser to get more CO2 in the water.

Related to this, is the metal halide lights better than flourescence? I would like to know before Friday, as it is my next day off and if the metal halide system is better I will go to one of the many shops around and buy one.

Could colour of light be algae cause? I do not use any Flora tubes, but I have them. Are they any good?
More light is better once your algae is under control. I have found it much easier to keep algae at bay using 130W over 129 gallons than I ever did with just 65W.

You may find that a lot of these mindless one size fits all prescriptions for algae prevention don't work for you. That's what I found.

"More CO2!" everyone said. Bah. I had plenty of CO2, killed a few fish, and I'll tell you right now, when people tell you "More CO2" they're just reciting the stuff they've read on this site from the REAL experts like Tom Barr.

Sometimes more CO2 is what you need. Sometimes it isn't. Just because you have black brush doesn't necessarily mean you are low on CO2 or that more of it will solve your issues.

At best all any of these suggestions will do is stop the algae from growing further. None of them will kill the algae. You have to either kill it with a solution like hydrogen peroxide or excel or clean it all out.

Then and only then IF your regime is correct will the algae stay gone and even then, many of us have resigned ourselves to living with green dust. I scrape it off the glass about every two weeks.

There's a whole entire set of so called cures for GDA too, and guess what? They don't always work. Some folks claim great success, others had no luck at all with these methods.

I just say all this to make you aware so that if you try these things and still have problems you know what's up and don't give up. Lots of people around here like to give out these solutions without any explanation or caveats or anything at all. It was frustrating as hell for me when I started my tank about this time last year.

Eventually I learned that even among the most seasoned experts there are heated debates about how to address the problem of algae in planted aquaria.
See less See more
If you go to your profile and allow people to email you I will send you an email with pics of some of my larger tanks. I am no where near as experienced as some people on here but I may be able to help out another Canuck! eh!
1 - 20 of 26 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.