Welcome to ScapeCrunch

We are ScapeCrunch, the place where planted aquarium hobbyists come to build relationships and support each other. When you're tired of doom scrolling, you've found your home here.

Help What am I doing wrong?

Joined
May 14, 2025
Messages
39
Reaction score
58
Location
United States
Ok guys and gals here it is.
36 gallon Bowfront, 30x15x22
Set up on 11/3/24
Water:
Ammonia 0
Nitrite 0
Nitrate 5~10 ppm
pH 7.6
KH 150 ppm
GH 150 ppm. This tell me almost all of my hardness comes from calcium
50% water change weekly, like religiously.
Equipment:
2 @ Marineland 200B, yes the bio wheels still spin and they are awesome. I have replaced the disposable cartridges with 2" 30 ppi Poret foam. Also both filters have Aquarium Co-op sponge prefileters.
150 watt Visitherm heater controlled by a cobalt aquatic controller. Set at 74. Keeps temps stable in the winter. In summer, this house has crappy insulation and A/C. Temps will swing 10 degrees inside on a hot day.
Lights: 2 @ 24" Finnex Planted + 3.0
These lights are currently set at 80% which gives me 25 par at substrate level, 22" depth. Lights are on for 4 hours, off 4, then on another 4.
Substrate: Standard inert aquarium gravel
Livestock: 4 black skirt tetras, 1 female swordtail, male Betta. Not my fish choices but good enough to cycle the tank and keep things stable for now. In the near future I'm hoping to get my real fish soon, some Laetacara curviceps, Lemon Tetra, and some hatchet fish.
Fertilization: 3 ml Aquarium Co-op Easy Green 2x per week, NilocG root tabs 1x per month, conservative on the root tabs.
Plants: Vallisneria spiralis, Anubias minima, Nymphaea rubra, Microsorum pteropus 'Windelov', Cryptocoryne wendtii Red, Echinodorus Red Rubin, Vallisneria torta, Vesicularia dubyana, Hygrophilia difformis, Vesicularia ferrieri, Süsswassertang, Lilaeopsis brasiliensis.
I had Red Root Floaters as well, but they all melted, probably due to too much surface agitation. I have purchased a couple of flow brakes to fit on the HOBs and that may help. I'll probably try floating plants again soon to shade some of the crypts and Anubias.

I have some algae issues. Probably from playing with the lighting. Algae on the glass isn't too bad after a week. I am starting to get some BBA on the Vals and some algae on Anubias. However hair algae on the moss gets long in a week. I manually removed it with a long bottle brush and I twirl it like spaghetti to remove it.
My sword plants were planted on 12/27/24 and literally have not grown at all. They arrived with emersed growth and transitioned within 6 weeks or so. They have put out a lot of nice small reddish leaves but the just aren't growing at all.
I do have a dual stage SR Aquaristik regulator and a 5lb tank sitting in storage. Wanted to stay rather low tech unless CO2 is the only solution.
My goal for this tank is just to have a nice display tank.
What am I doing right or wrong? Am I changing too much water and keeping nitrates too low?

IMG_20250513_090240772.webpIMG_20250513_090311899.webp
 
This tell me almost all of my hardness comes from calcium
May I ask how you're arriving at that? Is this tap water? You're at 8.4dKH and dGH which puts you in the moderately hard water category. Some of the plants you have would prefer softer water but I don't think this is overly important.

Lights are on for 4 hours, off 4, then on another 4.
Again, may I ask why you are turning them off for 4?

Standard inert aquarium gravel
Not ideal for rooting in. Some of your plants are heavy root feeders. Perhaps consider another inert substrate like BDBS or one of the soils?

Fertilization: 3 ml Aquarium Co-op Easy Green 2x per week, NilocG root tabs 1x per month, conservative on the root tabs.
I have no idea what this is putting in but I would suggest that you are not providing all the nutrients your plants may need. One thing that jumps out at me is that you may be low on the magnesium side but perhaps this is an area to focus on.

These lights are currently set at 80%
Trying lowering the power to 60%
 
Like @Art , I am also concerned about the fact that the lights are on for 4 hours and then off for 4 hours. This throws the photosynthetic mode into all the wrong gear. I think that even if the amount of fertilizer is sufficient, the disrupted photosynthesis cycle will work against you. Here is a table that will show you what you add to the aquarium with this fertilizer.

fert.webp
 
May I ask how you're arriving at that? Is this tap water? You're at 8.4dKH and dGH which puts you in the moderately hard water category. Some of the plants you have would prefer softer water but I don't think this is overly important.


Again, may I ask why you are turning them off for 4?


Not ideal for rooting in. Some of your plants are heavy root feeders. Perhaps consider another inert substrate like BDBS or one of the soils?


I have no idea what this is putting in but I would suggest that you are not providing all the nutrients your plants may need. One thing that jumps out at me is that you may be low on the magnesium side but perhaps this is an area to focus on.


Trying lowering the power to 60%
Art thanks for your reply.
When I test KH and GH it takes the same amount of drops to change color on the API test kit. It stands to reason then that calcium causes most if not all the hardness. The test is from the aquarium not tap water. It does vary some, I've had as few as 5 drops or oas many as 8 drops change the color.

I can provide you with a break down of the dosing in Easy Green. I have it in a spreadsheet somewhere, it states what every 1 ml provides. I just have to find that spreadsheet.

As far as lighting period I had read on PT.net that a siesta period was good. That vascular plants are able to use the light and nutrients quicker than algae. In fact that may come from Diana Walsted.
Is it better to have just one continuous photoperiod?

I know inert gravel isn't the best substrate for plants but it's what I had. I don't foresee investing in aquatic soil anytime soon unfortunately.

I can certainly turn down the lights and that will inhibit some algae growth, I'm just worried it's too dark at substrate level then, but very certainly worth a try.
 
Like @Art , I am also concerned about the fact that the lights are on for 4 hours and then off for 4 hours. This throws the photosynthetic mode into all the wrong gear. I think that even if the amount of fertilizer is sufficient, the disrupted photosynthesis cycle will work against you. Here is a table that will show you what you add to the aquarium with this fertilizer.

View attachment 8666
Thanks Stefan, that was the exact spreadsheet I just mentioned.
 
I keep both Co2 injected and non injected tanks…. It is definitely possible to keep non injected tanks relatively free of Algae.

5-10 ppm nitrates is not a bad target for a non injected tanks, however, Easy Green seems to trumpet their macros potency, yet their micros are a bit on the lighter side.

In my non injected tanks I do not dose nitrate or phosphate at all as the livestock and food provides plenty for me.

I dose Potassium weekly and micros much stronger than Easy Green…
I get Green Leaf Aquatics Edta and DTPA micromix powder and place 15 grams in a dosing bottle with 500 mls of distilled water and dose 2 mls per 10 gallons every other day and potassium Sulfate weekly after water change.

On the Co Op Forum lots of people talk about how much better their non injected tanks grow when they dose Easy Green at 30-50 ppm nitrates is. My guess is it aint the nitrate and phosphates that are helping so much as itis boosting the micros.

I would second Arts concerns about where your magnesium level is as well. Checking with your local wAter utility as to what their ppm of zca and Mg in your tap water would be worth the call..

After doing a significant water change I dose a loading dose of ferts into the tank to return the levels back to closer to where they were before water change and smaller amounts mid week.

It might be worth switching from the split photoperiod to a single photo period
 
Thats actually plenty of Mg. I dont run much more than that in my high energy stem tanks!

I havent gotten in to the details here to say more but youre in good hands with others above. Thats a nice little tank, there isnt much wrong
 
Thanks for the responses. Looks like we are going in the right direction.

BDBS can be found locally very inexpensively. I've seen it for around $13 for a 50 pound bag. Probably cheaper per pound than you aquarium gravel. Just a thought. Again, while I think this would help, I don't think it's the cause of your problems.

To continue our detective work, you have adjusted light levels down and now are using a full 8 hour photoperiod. I assume 1 pump of your fertilizer is putting in 1 ml so that the 3 ml you dose twice a week will match the table above. I would continue the fertilizer routine for now to see what the consistent but reduced light does. In a couple of weeks, re-assess.

On the KH and GH, I don't think it works that way. KH looks at carbonates in the water whereas GH is looking at total calcium and magnesium (for the most part). Your tap water plus what you're adding seems to be adding enough magnesium though.
 
Yeah, I agree with @Burr740 that there's a lot more going right than going wrong.

I am with you on the shading idea, and if floaters are too annoying to manage, consider a fast growing stem plant. I also think it's reasonable to just leave things and let the tank continue to mature. If your fundamentals are reasonable and you keep them consistent, things will improve over time as your happy plant mass increases.

Another option would be to get rid of the moss, if that is a constant eye sore. Java moss is so easy to get your hands on, you can always add it back later when the tank has progressed.
 
It can be worthwhile sending your water district an email to inquire if the calcium and magnesium levels stay fairly consistent to reported.

As I read it, those are maximum levels recorded and yet they report no range of results. The range is reported as n/a.

If this is pretty much what is delivered than supplementing calcium some to around total 25-30 ppm could be beneficial.

You report GH andKH at 150 ppm. What method are you using to test this, and have you tested both tank water and tap water, and do they test the same?
 
Last edited:
First things first, its not that YOU are doing anything wrong, this is a learning process and it takes time and patience, hang in there. There is a lot of bad, incorrect, and outdated information out there and it can be challenging to sort through it all. You've found a great place and many of the members here have a mountain of knowledge available. I'm by no means an expert, but seeing your post and having been in your shoes relatively recently felt I could provide some insight and maybe help you avoid making some of the same mistakes I made along the way. I may be incorrect with some of these observations, so hopefully someone more experienced can correct me if I'm wrong.

In terms of nutrients a good starting point is understanding Liebig's law of the minimum which states that the growth of an organism, such as a plant, is limited by the scarcest resource, or limiting factor, rather than the total amount of resources available. This principle highlights that even if other nutrients are abundant, growth will be poor if one essential nutrient is deficient. To help visualize this think of a barrel of water, each board that makes up the barrel represents a different nutrient (N, P, K, Etc).

1000004920.webp

If you KNOW that all your nutrients are taken care of then it leaves you with only 2 other inputs to consider, light & Co2.

Your water is pretty hard. Very similar situation I was dealing with. In hard higher pH water it becomes more difficult for plants to uptake certain nutrients. More on this in a moment. You can certainly still grow plants in this water. I personally chose the dilute my tap water with Reverse Osmosis water to lower my pH slightly but also soften the water some.

While your large gravel is not ideal, many plants can still be grown. I am still using pea sized gravel gravel in my low tech but personally I will probably only be using aquasoils moving forward only using gravel and sand for aesthetics & details, not as the primary substrate for plant growth. The growth I've seen from just switching to aquasoil has been incredible, even without use of excel or co2. For now though, lets work with the substrate you have in the tank.

Root tabs have helped me some, but I only usually replace them once about every 3 months. I mostly rely on water column dosing fertilizers. I have also tried using easy green, as well as the seachem line of fertilizers, probably a couple others along the way. When I finally began to find better success was once I started buying the dry salts to mix my own fertilizers. These are much cheaper in the long run and while it may seem confusing at first, its actually much easier than you might think. There are plenty of people here than can guide you through using rotalabutterfly to calculate your mixes. Mixing your own fertilizers allows you the ability customize your dosing to YOUR tank and adjust the ratios as needed. I have very high nitrates from my tap water, and dosing easy green for me was only increasing the nitrates. I ended up making my own fertilizers without nitrate until the plants were growing healthy enough that they were using up all the nitrates from the tap water and I had to slowly begin adding nitrate back into my fertilizer mix. As I mentioned earlier certain nutrients become difficult for the plants to uptake if your pH is higher, like Fe EDPA, DTPA, etc.

Next your tank is pretty deep and you are not heavily planted, with most of the plants located only in the bottom 25-50% of the tank. There is a lot of light available in the top 50-75% of the water column with no plants to use that available light.... the algae will gladly find a use for it. With that said, what are you expectations? Zero algae? In my opinion a little algae is acceptable and to be expected, especially if its growth is naturally limited in a balanced tank. If things are out balance then it will have a ability overtake a tank. I only recently began using co2, but on my low tech tank I used excel as a carbon supplement (NOT a co2 replacement) with very low light levels. I have never used a "siesta" period, I've read of many people doing this, but its not something I can speak on. The amount of Co2 that might be produced during this siesta is probably minimal and would be used by the plants probably within the first 20mins of the lights coming back on. Running 2 planted tank lights at 80% in my opinion is probably way too much light if not injecting co2. If you view Light as the gas pedal, then co2 is the gas. Co2 is VERY limited in a low tech tank, if you crank up the lights then you run out of gas, and in this low co2 environment algae has the advantage.
I would highly suggest reading Tom Barr's article "Non Co2 Methods" as he writes:
"If we added more light then the CO2 would start becoming a more limiting factor and allow algae to grow better (algae need higher light to grow well in non CO2 enriched systems where as the plants are much more limited without CO2). A lower light level is required...
CO2 will limit plants much more than algae, the lower light(the only limiting factor for algae in planted tanks really) and high plant biomass density will provide a better place for the plants and a worse place for the algae. CO2 and non CO2 tanks work well and are algae free namely due to high plant biomass that is relatively healthy....
...Over time, the plants, adapt well to low CO2 ppm concentration by producing more Rubsico and associated downstream enzymes to fix and make do with much less CO2 than a CO2 enriched system...
...As long as the CO2 is stable, things are fine. Large water changes tend to add a spike of CO2 and this can cause instability. Perhaps algae sense changes in CO2/low O2. Speculation certainly...
...Doing water changes adds CO2 back to a CO2 limited tank.
Plants and algae both can and do adapt to low CO2 environments and induce genes to make enzymes that concentrate CO2 around Rubisco, the CO2 fixing enzyme. When we add the CO2 at higher levels back, this causes the plants and algae to destroy the low CO2 enzymes and start growing without of them since they no longer need them to fix CO2 from the KH ( the -HCO3).
Why keep all this machinery around if you no longer need it? Doing weekly water changes "fools" the plants and helps encourage algae more. Algae are faster to respond to low CO2 than plants.
Once the plants do adapt, they can do well." -Tom Barr "Non Co2 Methods"
 
It can be worthwhile sending your water district an email to inquire if the calcium and magnesium levels stay fairly consistent to reported.

As I read it, those are maximum levels recorded and yet they report no range of results. The range is reported as n/a.

If this is pretty much what is delivered than supplementing calcium some to around total 25-30 ppm could be beneficial.

You report GH andKH at 150 ppm. What method are you using to test this, and have you tested both tank water and tap water, and do they test the same?
I test my water with the API Master Test Kit. It's fairly new so the reagents are still viable. I last tested my tap water a couple of months ago. Maybe I should have waited 24 hrs to test the tap? Out of the tap pH 6.8, KH took 11 drops (196.9 ppm) and GH took 14 drops (above 200 ppm).
The actual aquarium water does test lower than the tap. That seems normal as BB use some calcium during their biological processes and most tanks tend towards softer more acidic water as they mature. Obviously it's hard enough that there enough buffer to prevent a pH crash.
I can run another set of tests this afternoon.


First things first, its not that YOU are doing anything wrong, this is a learning process and it takes time and patience, hang in there. There is a lot of bad, incorrect, and outdated information out there and it can be challenging to sort through it all. You've found a great place and many of the members here have a mountain of knowledge available. I'm by no means an expert, but seeing your post and having been in your shoes relatively recently felt I could provide some insight and maybe help you avoid making some of the same mistakes I made along the way. I may be incorrect with some of these observations, so hopefully someone more experienced can correct me if I'm wrong.

In terms of nutrients a good starting point is understanding Liebig's law of the minimum which states that the growth of an organism, such as a plant, is limited by the scarcest resource, or limiting factor, rather than the total amount of resources available. This principle highlights that even if other nutrients are abundant, growth will be poor if one essential nutrient is deficient. To help visualize this think of a barrel of water, each board that makes up the barrel represents a different nutrient (N, P, K, Etc).

View attachment 8694

If you KNOW that all your nutrients are taken care of then it leaves you with only 2 other inputs to consider, light & Co2.

Your water is pretty hard. Very similar situation I was dealing with. In hard higher pH water it becomes more difficult for plants to uptake certain nutrients. More on this in a moment. You can certainly still grow plants in this water. I personally chose the dilute my tap water with Reverse Osmosis water to lower my pH slightly but also soften the water some.

While your large gravel is not ideal, many plants can still be grown. I am still using pea sized gravel gravel in my low tech but personally I will probably only be using aquasoils moving forward only using gravel and sand for aesthetics & details, not as the primary substrate for plant growth. The growth I've seen from just switching to aquasoil has been incredible, even without use of excel or co2. For now though, lets work with the substrate you have in the tank.

Root tabs have helped me some, but I only usually replace them once about every 3 months. I mostly rely on water column dosing fertilizers. I have also tried using easy green, as well as the seachem line of fertilizers, probably a couple others along the way. When I finally began to find better success was once I started buying the dry salts to mix my own fertilizers. These are much cheaper in the long run and while it may seem confusing at first, its actually much easier than you might think. There are plenty of people here than can guide you through using rotalabutterfly to calculate your mixes. Mixing your own fertilizers allows you the ability customize your dosing to YOUR tank and adjust the ratios as needed. I have very high nitrates from my tap water, and dosing easy green for me was only increasing the nitrates. I ended up making my own fertilizers without nitrate until the plants were growing healthy enough that they were using up all the nitrates from the tap water and I had to slowly begin adding nitrate back into my fertilizer mix. As I mentioned earlier certain nutrients become difficult for the plants to uptake if your pH is higher, like Fe EDPA, DTPA, etc.

Next your tank is pretty deep and you are not heavily planted, with most of the plants located only in the bottom 25-50% of the tank. There is a lot of light available in the top 50-75% of the water column with no plants to use that available light.... the algae will gladly find a use for it. With that said, what are you expectations? Zero algae? In my opinion a little algae is acceptable and to be expected, especially if its growth is naturally limited in a balanced tank. If things are out balance then it will have a ability overtake a tank. I only recently began using co2, but on my low tech tank I used excel as a carbon supplement (NOT a co2 replacement) with very low light levels. I have never used a "siesta" period, I've read of many people doing this, but its not something I can speak on. The amount of Co2 that might be produced during this siesta is probably minimal and would be used by the plants probably within the first 20mins of the lights coming back on. Running 2 planted tank lights at 80% in my opinion is probably way too much light if not injecting co2. If you view Light as the gas pedal, then co2 is the gas. Co2 is VERY limited in a low tech tank, if you crank up the lights then you run out of gas, and in this low co2 environment algae has the advantage.
I would highly suggest reading Tom Barr's article "Non Co2 Methods" as he writes:
"If we added more light then the CO2 would start becoming a more limiting factor and allow algae to grow better (algae need higher light to grow well in non CO2 enriched systems where as the plants are much more limited without CO2). A lower light level is required...
CO2 will limit plants much more than algae, the lower light(the only limiting factor for algae in planted tanks really) and high plant biomass density will provide a better place for the plants and a worse place for the algae. CO2 and non CO2 tanks work well and are algae free namely due to high plant biomass that is relatively healthy....
...Over time, the plants, adapt well to low CO2 ppm concentration by producing more Rubsico and associated downstream enzymes to fix and make do with much less CO2 than a CO2 enriched system...
...As long as the CO2 is stable, things are fine. Large water changes tend to add a spike of CO2 and this can cause instability. Perhaps algae sense changes in CO2/low O2. Speculation certainly...
...Doing water changes adds CO2 back to a CO2 limited tank.
Plants and algae both can and do adapt to low CO2 environments and induce genes to make enzymes that concentrate CO2 around Rubisco, the CO2 fixing enzyme. When we add the CO2 at higher levels back, this causes the plants and algae to destroy the low CO2 enzymes and start growing without of them since they no longer need them to fix CO2 from the KH ( the -HCO3).
Why keep all this machinery around if you no longer need it? Doing weekly water changes "fools" the plants and helps encourage algae more. Algae are faster to respond to low CO2 than plants.
Once the plants do adapt, they can do well." -Tom Barr "Non Co2 Methods"
Wow thanks for the info. That's a lot to digest. I don't mind algae, I know it's a natural part of every aquatic ecosystem. I don't care if it grows on the glass or rocks or wood. However I realize algae only attacks unhealthy leaves and unhealthy leaves are a symptom of an unhealthy plant.
To be honest I switched to the Easy Green out of convience. When I first set up this tank for the first few months I used NilocG DIY EI Ferts. I had some leftover from the previous time I set up this aquarium. I switched simply because I thought it would be easier to just use an all in one fert.
I still have the mixing/dosing bottles so eventually maybe it's better to switch Ferts? For now I'll use the rest of the Easy Green till it's gone.

Maybe I should cut back on the water changes?
 
Can some more people elaborate on the water change/algae relationship? Everything I’ve read and seen say that water changes are your best friend when dealing with an algae outbreak, but the above Tom Barr quote says the opposite. I would like more info…
 
above Tom Barr quote says the opposite.

Well Tom posted that literally 20 years ago.

Since that time it has been established that the primary trigger for algae proliferation is the presence of dissolved substances that have been ejected from the surface of injured and aging plant leaves, as the plant withdraws support from those leaves.

The substances are literally a chemical signal in the water that tells algae spores there's food out there, and it's a great time to wake up and start making baby algae cells.

Removing those signaling substances from the water reduces the ability of algae spores to germinate and turn into algae outbreaks.

That's what your water change buys you, you are removing those organics from the water.

Now, in a slow growing tank, without a lot of opportunity for big CO2 fluctuations causing leaves to constantly internally rewire themselves, leaves get stressed less. And if you regularly prune your leaves as they age, you don't have a lot of dying plant mass.

Both of those things mean those triggers are suppressed. So you can potentially change the water much less frequently than a higher growth rate tank if it's carefully maintained.
 
Last edited:
With all due respect for @plantbrain and his comments, which I'm sure were scientifically true, I would suggest reading @sudiorca's journal entitled Sudiorca's Non-CO2 Supplemented Softwater Tanks and, perhaps, reaching out to them. I always like to speak to someone who actually keeps the type of tank I'm interested in and I can see their results.

He discusses this topic and @*Ci* references Tom's article in this post on Rubisco.

I have no where near the scientific understanding or knowledge, however, I have learned that plants adapt well to consistent actions. I would suggest that weekly water changes will do more good for your ecosystem than less frequent ones. I tested that theory back in the day and got lambasted on Facebook. Your plants will adapt to the rhythm of your husbandry.

If they don't, you will clearly know it.
 

Top 10 Trending Threads

Back
Top