Journal Recovering from disaster: My 120P journey.

[bradquade]

About me:
I've been keeping planted aquariums and shrimp breeding tanks for almost a decade and for the majority of that time aquariums were my primary hobby. In 2021 I had ~30 tanks running simultaneously containing almost 200 types of plants that I had collected over a 5 year period and more than a dozen types of shrimp. In this time, it was harder for me to not setup new tanks than it was to grow any aquatic plant sent my way. Below are some of the tanks I've kept over the years.






At the end of 2021 I moved from Texas to Massachusetts and gave away all of my plants, tanks, and shrimp to friends I had made over the years. It took some time to find a permanent place to live so I didn't have any tanks until I was unexpectedly given an ADA 120P in summer of 2023.

The early days of the 120P:
I went through the typical tank start growing pains with a diatoms phase, green hair algae, and every other issue one would expect from a new tank. Even with the new tank difficulties, it only took me 2 months to get to a healthy tank again. For the next 1.5 years, everything went smoothly and the tank went through many iterations.

Setup on June 28th

Diatoms outbreak on July 19th

Green hair algae outbreak by August 18th

Everything was cleaned up and growing great by September 1st

The start of the disaster:
In February 2025, I started running into issues. BBA started growing in small tufts on the substrate and green hair algae started attacking the old growth on the plants. I'd run into this issue in the past and was usually able to fix it pretty quickly by dialing in the CO2, cleaning the substrate, cleaning filters, and replanting only the most healthy tops of the plants. Even after doing this multiple times, I haven't had any luck fixing the algae. It always comes back


The start of the algae

Multiple trim and replant cycles along with some new plants

Relatively clean after a trim and replant cycle

10 days later

Where I am today:
I'm getting so frustrated by the persistent issues that I'm about ready to shut down this tank. As a last ditch effort, I purchased a pack of healthy plants from Burr740 to see if healthy plants can help me get through the algae phase and get back into a good place.

The tank as of January 2nd 2026. The healthiest plants in the tank were received earlier this week from Burr740.

Really poor color on my plants with a lot of green algae on the lower leaves. The nice looking bacopa is from Burr740. The original stems of Bacopa have barely grown in the last month. If I pull them up, there are very few roots.

Another example of the old growth issues. The Limnophila mini vietnam also has not grown at all in the last month. Lots of algae grows on the substrate as well.

Another comparison of Burr's Ludwigia sp. red vs mine. Very slow growth and poor rooting.

Really weak older growth on Rotala sp. singapore and poor coloration compared to Burr's plants. This plant has always been very easy for me to keep and this is part of why I'm thinking there is something big that I'm missing. Didiplis diandra is another easy plant that keeps melting at the base and its making very little progress because of this.


Below is the key information about the tank.
Tank size: ADA 120P (120 cm x 45 cm x 45 cm)
Lighting: 3x NiloCG Prizms ran at the lowest setting for each channel. Lights are on for 7 hours a day. I want to increase the lighting, but any time I do the algae gets significantly worse
Filtration: Oase Biomaster 600 and a SunSun HW-303B. There's a spraybar on the bottom left that points along the length of the tank at substrate level and the other output is on the top right corner of the tank pushing the opposite direction.
CO2: Vertical reactor on the SunSun filter and a Sera reactor on the Oase. CO2 comes on 4 hours before lights on and turns off 1 hr before lights off. Drop checker is yellow when lights turn on. The pH drop is ~1.4-1.5 at lights on (5.8 at lights on and 7.3 when water is fully degassed). Plants start pearling within 10 minutes of the lights coming on.
Substrate: A mix of ADA aquasoil, Fluval stratum, and Controsoil. A bag of Controsoil was added ~2 months ago to try and give the plants a boost. The remaining substrate is from when I setup the tank and is almost certainly not providing much nutrition or buffering capacity.
Water change schedule: Weekly 70-80% water changes with tap water coming from the MWRA (water report here). KH is ~2. GH is less than 1(3.7 PPM Ca, 0.7 PPM Mg based on the report). Water is treated with sodium carbonate at the water treatment plant to increase the pH to ~9.2, but the pH rapidly decreases after the water comes out of the tap. One potential issue is the tap water is extremely cold. It comes out at ~50F and I add a mix of water from the tap along with heated water. The temperature drops to ~60F for 2-3 hours whenever I water change. I don't keep any livestock so I'm not sure if this is a problem. This was not something I needed to consider back in Texas.
Remineralization: I add 22 PPM calcium and 6 PPM magnesium at water change
Fertilization: 20N-6P-26K is added immediately after water change. A second dose at 10N-3P-13K is added halfway through the week. Micros are Burr740's most recent recipe dosed at 0.15 PPM Fe 3x per week.
Temperature: Tank is heated to 73F during the winter. During the more mild parts of the year I remove the heater and go with whatever the ambient temperature is.

It looks like I'm doing everything right on paper and based on my past experience keeping tanks, but there is clearly some major issue ongoing. Right now I'm thinking its inconsistency in the CO2 that I'm just not seeing (I just started the CO2 2 hours earlier last week because I was noticing the drop checker wasn't always yellow at lights on), not enough light, or too cold of water during water changes. I want to keep some records through this journal to keep myself engaged with the tank and to make sure I'm being consistent with everything. I'm also hoping some additional eyes can help me see where I'm going wrong because I really, really miss having a nice looking tank.

 

[Koan]

tap water coming from the MWRA (water report here)

I'm a little concerned about the possibility of sodium toxicity



They talk about using two sodium products in their sterilization process, and there's a huge variation in sodium levels across their samples from different reservoir sources in this October snapshot report.

Given that this was working for a while and then it wasn't, I'd be worried that some variation in that has shifted, upstream of your tap, around the time this started happening.

Whether it's sodium or something else, going with RO water for a couple of months would give you a total control over the soup you're serving these plants, and maybe save your sanity

Here are some forum discussions on RO units

Thread 'Home RO set up for aquarium and drinking'

Jul 29, 2025

Looking for recs on RO set up

Needs

• water for a 29 and 23 gallon tank
• not doing auto top off
• weekly water change of about 50%
• planning to use it also for drinking for a 4 family household so need some way to remineralize it
• looking at under the sink option in our kitchen but not necessarily sure how I would store the water

Would be great if people can share their experience with similar setups

Thank you

• Sb1415
• Replies: 20
• Forum: Equipment Discussions

Low Tech Tank Post in thread '10g Chrome Metaframe'

May 10, 2025

How has this RO system worked out for you? Considering something similar.

It’s great. This is the brand and model I bought:
Waterdrop G3P800 | Tankless Reverse Osmosis Water Filter with UV Sterilization

I use it for all my drinking water as well, re-mineralizing it with trace minerals:

Aussie Trace Minerals Canada

I like the tankless feature, no fear of bacterial growth in the storage container, and it is super easy to change the cartridges. However, if you want to use it for a bigger fish tank, it would be pretty slow to refill. It’s fine for my 10 g tank and for a...

• *Ci*

Thread 'Recommendations for at Home RO Water Unit'

Aug 29, 2023

Greetings,

I am very interested in installing a RO water unit on my hose splitter in the back yard. I want to avoid using any of my sinks inside. I recall people recommending certain units a few years back but that online store has closed down and I am curious if there are better units now. Recommendations would be helpful if you have one you think would make sense for an outdoor garden hose valve.

• Grobro
• Replies: 11
• Forum: Equipment Discussions

 

[Kwyet]

Also, gH less than 1 seems problematic to me. I think most try to keep it around 5 at least.

 

[Sb1415]

Your prior tanks were awesome and with so much experience I am sure you are going to get over this.

Along the line of what @Kwyet said, switching to RO would make lot of sense. What is your GH currently in your tank? Assuming you dechlorinate but wanted to check. Did you happen to add a water softener to your home system ? That can mess up the parameters as well.

Overall it seems that something threw of your stability and it seems that your water might be the one thing that you could standardize as well to see.

If you do go down the RO system, I think many here have had good experience with the regular tank RO system. Myself, after getting input here at Scapercrunch from another user @Ci got a tankless system which I also use for drinking. If you end up deciding on the tankless, happy to answer any questions. I have been very happy with it.

 

[Ernesto]

Remineralization: I add 22 PPM calcium and 6 PPM magnesium at water change

so if this is correctly scaled on tank volume, GH should be at least at 4.46 (calculator)

 

[bradquade]

Thanks all that have responded so far. Getting these perspectives is exactly why I wanted to make the journal.

@Koan @Sb1415 I have an RO system from back in my Caridina shrimp breeding days. I still use it for my small tanks and to prepare water for my houseplants. I've always tried to avoid RO water for large aquariums because it makes it difficult to do multiple water changes after rescaping, which I tend to do often. It seems like switching to RO is a popular suggestion though and I will end up going that route. I'll grab a barrel from the store, make some water, and give this a shot for a couple months. This will also give me the chance to thoroughly heat water change water before adding it to the tank and I can rule out cold shock as a potential issue.

I will admit that I'm not entirely convinced that RO will be a game changer. The water report makes it look like the water composition changes, but its trying to illustrate before and after treatment in two water systems. Column 4 is the relevant one because I'm in the Wachusett system after the Carroll Treatment plant and this column has a similar composition across historical water reports. The tank went downhill at the time that I would expect substrate to run out of nutrition/buffering capacity and I wonder if the active substrate was protecting against something negative in the tap. We will see soon enough. Hopefully RO works better than I expect and I can make a positive post in the near future.

@Kwyet I add 22 PPM Ca and 6 PPM Mg to the tank after every water change. I add it based on total tank volume so when accounting for water change volume there is some accumulation to ~ 30 PPM Ca and ~9 PPM Mg. This should be a fairly reasonable amount and I'll stick with it when I make the switch to RO.

 

[Koan]

Right now I'm thinking its inconsistency in the CO2 that I'm just not seeing

Using the Hanna CO2 kit, to directly measure CO2 instead of inferring from pH drop, can also remove this uncertainty for you

Resource Thread 'Hanna CO2 Test Kit: My experience so far (and why you're probably not starting CO2 injection early enough)!'

Mar 27, 2025

The 2hrAquarist legend Dennis Wong tested the Hanna Test Kit vs a $3,000+ CO2 testing device and found accurate results in low kH aquasoil based tanks when compared. $30 for CO2 readings vs $3,000+!

It's a simple kit that comes with simple instructions, two differently sized vials for different detection ranges, a titration syringe phenolphthalein indicator, and an NaOH solution of some unknown concentration to titrate with.

For the range of detection on the Hanna CO2 test kit we want (0-50ppm):

• Add 10mL of aquarium water to the small flask. Add 1...

• Naturescapes_Rocco
• co2 co2 measurement hanna injection test kit titration
• Replies: 39
• Forum: Fertilizing and Aquarium Chemistry

• 
• 

 

[BenB]

I read your posts, and we have a lot in common lately. However, I always grew in an inert substrate. So a year ago, I decided after a long absence from the hobby, I would get back going, but this time I wanted to try aquasoil. Like you, I've been doing this for decades. I know what I'm doing. None of my tanks were ever as nice as yours, but I grew great plants for years with little algae. This time I grew, THIS. I finally figured it out only for it to go to crap a second time. I figured that one out too and my tank looked amazing.... only for it to go to crap worse than the previous time. Now, I've figured that one as well and everything is getting back on its feet. So keep going, you'll get it nailed down at some point.

As far as using the RO for water changes. Just give it a shot for a few cycles. If it doesn't help, then at least you've eliminated your tap water as part of the problem.

Also, the CO2 test kit is great. I don't use the Hannah, but I use a similar one. It has really helped me to dial in my CO2.

 

[bradquade]

@BenB I read through your posts and it is a similar situation. Isn't it annoying knowing you can do better, but not being able to get there? With some more work and the help of the community, I think we can both solve our problems.

Yesterday I got a water barrel for RO and made a big bucket of RO water. Tap going in is 81 PPM and coming out its 5-6 PPM. The RO membrane is probably 7 years old at this point and should be replaced and my DI stage is completely tapped out. This reduction in TDS should be sufficient to see if the tap water is an issue though.

I was able to do the first RO water change this morning. Before water changing the TDS was 290 PPM and after adding the RO water it was 81 PPM. This suggests a roughly 70% water change, which would bring the sodium level down to ~9 PPM. Since I don't keep any livestock I remineralized in the tank with 22 PPM calcium and 6 PPM magnesium. Accounting for accumulation and 70% water change volume, I should max out at 30 PPM calcium and 9 PPM magnesium. I also dosed 20 PPM nitrate, 6 PPM phosphate, and 26 PPM potassium along with a 0.15 PPM Fe dose of Burr micros. I'll make sure the drop checker is yellow at lights on and the pH drop is greater than 1.2. If that's the case, everything should be in a range to begin seeing some positive changes. The RO was also preheated and the tank dropped to 64F after water change instead of the 50s. This is much more reasonable and should be enough to rule out cold water as an issue.

If the algae grows like crazy, I'll water change again Wednesday. If everything goes smoothly, I'll do a macro dose at half of the values listed above on Wednesday and 2 more micro doses before next weekends water change. Below is a picture of the tank as of the morning for record keeping purposes. I'm really hoping to see some positive growth on the plants so I can start aggressively trimming the algae covered growth.

 

[BenB]

@BenB I read through your posts and it is a similar situation. Isn't it annoying knowing you can do better, but not being able to get there? With some more work and the help of the community, I think we can both solve our problems.

Definitely. For me a big learning point with my issues was that the answer isn't always the usual, well how much CO2 or NO3 are you dosing kind of problem solving. The first time my K2SO4 was really KNO3. You can't grow plants with almost no K. The second time it was my water temp. This last time it seems something had screwed up my ferts. I remade my macros and trace and within a day, you could tell everything was turning around. So like with the RO, if you've eliminated all the usual suspects, start looking at other things.

If everything goes smoothly,

This is really vague, but all 3 times, when my plants were getting what they needed, the quality of the pearling changed. Instead of random bubbles here and there, it seemed more purposeful. I know that sounds stupid, and I'd never tell a newbie that, but I think when you see it, you'll know what I mean. Months back when the first disaster was resolving, I could just tell from the pearling I had figured it out and it was just a matter of a lot of manual removal and time.

 

[Naturescapes_Rocco]

This is really vague, but all 3 times, when my plants were getting what they needed, the quality of the pearling changed. Instead of random bubbles here and there, it seemed more purposeful.

This is a HUGE reason why I like high-energy tanks. I can use pearling as a really good indicator for general plant health and wellbeing -- In a low tech tank, where you might not find out you screwed up for weeks due to no visible pearling, I don't have the patience!

Even though it comes at a cost of more potential issues should something fall out of balance, and requires weekly water changes and more trimming, I really do feel like I love aquariums that pearl, heavily.

 

[bradquade]

Pearling is the best indicator of general health in a high energy planted tank and is something that should be closely monitored. I totally agree with this. As Rocco mentioned, intensity of pearling often changes before there are visual changes in plant health, making it a particularly good way to keep an eye on the tank. When I'm having problems (like right now) I often go to the tank, turn off the flow, and watch the bubbles coming from the plants. I have many videos of the pearling in my tanks so I can compare over time and see if there are any trends. I've also found that it's helpful to keep HC during times of struggle because the new growing tips always have oxygen bubbles when everything is in order. Right now I'm keeping a patch of HC partially emersed in one of my low tech tanks and I periodically move bits into the 120P so I can see if the growing tips have oxygen bubbles. Yesterday I checked the pearling in the 120P multiple times and it seemed much more purposeful and intense than I've seen recently. I found this very encouraging, but I need to see a consistent trend before I'll be happy.