Low Bioload and High Plant Load

[egruttum]

I have 5 separate tanks all with similar issues but potentially different solutions based on the livestock.   Basic question is how do I keep enough macro nutrients for the plants while being cognizant of the livestock that I have read is a little more sensitive (Apisto, gudgeons).  I use root tabs and Easy Green but the math says one pump of Easy Green is about 3 PPM nitrates.  I don't want to just keep squirting.

1. 20 gallon planted (low-med light) (tank in picture)- This has 7 guppies, 2 BN pleco, and 1 female Apisto Cacatuoides.  I dose 2 weekly pumps of Easy Green but my nitrates are always zero.  With the Apisto (brand new) I am afraid to dose any higher or with anything else based on reading a lot of them needed clean water and lots of water changes.  My current water change is about 20% every other week.  How do I keep 20 PPM nitrates for plants with more planned more frequent water changes for the apisto?  Or am I over-estimating the water change needs for it?

2. Two 10 gallon tanks (med light each) (5 peacock gudgeons in one, 20 red cherry shrimp in the other)- I would describe these are medium planted including floaters (XL water lettuce and frogbit, respectively).  I have a few swords in each so they get root tabs monthly and a pump of Easy Green weekly.  Maybe 10% bi-weekly water change in the gudgeons and I plan about 10% monthly water change (and top ups) for the shrimp.

3. One 10 gallon tank (low light) (no livestock, not sure what i will do with it).  This tank is easiest to mess with because its empty of livestock.  I keep the hornwort (fills about 2/3 of the tank), dwarf water lettuce, and nitrifying bacteria fed constantly with a 3% ammonia solution to take the aquarium to 4 PPM daily.  I randomly change water in here as I feel like it.  24 hours after my NH3 addition the NH3, NO2, and NO3 are all zero.  I also dose Easy Green one pump per week.

If you read this far Thank You!

[ChemBob]

I had a similar issue in my 40 gallon. I was not getting enough nitrates for my plants and ended up with an algae issue. I ended up spiking the tank up to 20 ppm. I took quite a bit of Easy Green. I did a set of squirts, I think between 4 and 8, wait 20 or 30 minutes, then tested. Repeat. I did this until I got 20ppm on my test strips. 

I have also changed from 4 pumps once a week to a pump every day. This seems to be keeping the plants happy and is working with my plant and fish load. I am adding more fish soon so will probably cut back to every other day. Spreading the dosing out keeps things a bit more stable in the tank vs a big spike in ferts once a week.

Play around to see what works on your setups. Don't change too many things too quickly, otherwise you won't know what worked and what didn't. 

[Isaac M]

Hi @egruttum, what do you use to test your nitrates? If it is the API test kit, I would be sure to read the instruction as not shaking one of the bottle (i think #2 for 60 seconds) will give you a false zero reading. 

Also, for water changes, I would do them when the nitrates get over 40 ppm. 

If your plants are not showing signs of nutrient deficiencies, I would not be too worried about trying to add more easy green. 
 

I will add some links below to some aquarium co-op blog posts that may be helpful resources:

https://www.aquariumcoop.com/blogs/aquarium/plant-nutrient-deficiencies
 

https://www.aquariumcoop.com/pages/water-changes

 

[Isaac M]

Hi @ChemBob, very wise advice. As for the Easy Green dosing, this will depend on how heavy your plant load is along with your lights and carbon dioxide levels. One of those will be the limiting factors, if you do not have enough established plants, carbon dioxide and lighting for the amount of nutrients you are dosing, algae will ensue. It is all a balance of those factors.   

[Mmiller2001]

Keep in mind that Nitrates from fish and Nitrates from fertilizers need be thought of as different. If you are testing 0 to low nitrates, don't be afraid to dose to your desired target. Dosing ridiculous amounts of fertilizers has been tested on fish and you would have to dose an insane amounts to see any problems.

I encourage your own research, and would suggest searching for Tom Barr. He developed Estimative Index fertilization, that essentially over doses nutrients. He has also ran experiments to back up his results.

Edited May 3, 2021 by Mmiller2001

[egruttum]

Thank you everyone for the info.  @Isaac M thanks for the links.  I had seen the nutrients one but never saw the water change one.  I'm guessing I will be on the monthly 15% water change for my aquariums unless I do some thing drastically different in any of them.  I should have known the answer would be "less is more".  We all want to do as much active work as possible but so many times being passive and monitoring is the right thing to do with an aquarium.

I'm guessing CO2 will be the limiting factor in all of my aquariums so I will make sure to monitor fertilization based on CO2 being the limit.

@Mmiller2001 I will look up Tom Barr.  I have heard about EI before but never looked into it.  I will take a look but I'm guessing I will be passive at this point.  With no CO2 (and no desire to start at this point in life) I will keep my Easy Green dosing schedule and go from there.

@ChemBob I try to space my squirts out by 3-4 days in my 20 gallon like you suggest.  

As my Dad taught me, "No good deed goes unpunished".  In this case all is well in my aquarium so I will leave them alone.

Thank you everyone for the responses.

[Mmiller2001]

37 minutes ago, egruttum said:

@Mmiller2001 I will look up Tom Barr.  I have heard about EI before but never looked into it.  I will take a look but I'm guessing I will be passive at this point.  With no CO2 (and no desire to start at this point in life) I will keep my Easy Green dosing schedule and go from there.

EI can be implemented on low tech tanks; just a few adjustments in dosing totals is needed. I use EI on my low tech tanks. Just FYI.

[Isaac M]

I agree @egruttum, fish keepers love having their hands in their aquarium haha being consistent and letting nature do all of the work is my go-to now. Same with plants, there are many ways to grow plants really well and fast but I do not want to be trimming plants every week. I like just being able to feed my fish and watch the aquarium. I even use dirt in my substrate so that way I do not have to dose fertilizer into my aquarium 😂 less is more with dirt as well haha all I do now is feed my fish, watch them and test the water. 

[Isaac M]

By the way, this is the thread to my 40 gallon aquarium that has 5 sterbai corydoras and a lot of shrimp. I would consider this to be a low bioload high plant load aquarium as well.