Nitrate supplementation between tanks?

[Bumblebeeatrice]

Hello! New community member here. I lurk on these threads a lot and made a profile specifically for this question. Please be patient, I studied art in school and haven't taken a science class in years, so if my thought process is off please let me know!

Relevant info: I have two tanks at home, a heavily planted 5 gallon shrimp tank and a medium planted 10 gallon community tank with snails.

My shrimp tank is going great, with one problem: the plant growth is INCREDIBLY slow. I have some stems in there that should grow quickly, from everything I've read. There is no sign of nutrient deficiency, but the plants are growing slowly enough that diatome algae is growing on everyone's leaves. I have a light on 12 hours, have some (maybe not enough) flourish tabs in the substrate, dose with api leaf zone once a week, and the a/n/n is always 0-0-0. I think the plants may be depleting the water column completely of nitrates and still wanting more. I have a better fertilizer coming that should help with the nitrate problem, but it won't be here for another few weeks and I like to experiment lol.

Here's where my 10 gallon comes in. I recently had a clutch of bladder snails hatch, and then another, and maybe even another. I've been plucking out as many as I can every time I feed my other snails, but there are still quite a few. My rabbit snail has also been eating my stems, so those aren't growing as well as I hoped they would. Additionally, one of my rooted plants (some type of valsinera maybe?) Is showing signs of potassium deficiency and hasn't been growing too great either. This has caused my nitrates to skyrocket. I performed a 25% water change yesterday and measured afterwards, and they're still around 40ppm. I'm going to do another 50% water change tonight. I've plopped a hornwort sprig in there to help absorb excess nutrients, stuck a pothos cutting in the filter box, and added a pad of crystalwort to help mitigate the nitrates and hopefully get the tank more balanced until I can rid of more snails.

Maybe you can see where I'm going with this. One tank with no nitrate, one tank with way too much.

In the absence of a fertilizer, I'm wondering if I could take some of my 10 gallon tank's water and drip it into my 5 gallon? I don't want to exceed 5ppm, but my goal is around 3ppm.

So here's my list of real questions:
1: Does water chemistry work in a way that would allow this kind of supplementation?
2: Ignoring plant absorption as a variable, how much 40ppm nitrate water should I drip into a 5 gallon tank to bring 0ppm up to 3-5ppm?
3: If everything goes well and I want to supplement my 5 gallon this way in the future, what kind of math do I need to do? Is there an equation that would help me figure it out on my own?

 

[Aiken Drum]

On the face of it, every 2.5% water change you do to your 5g with water from the 10g tank should raise the nitrate by 1ppm. So a 12.5% water change should raise the nitrate to 5ppm.

Im not sure you would see any benefit though. Your plants will likely quickly take up this up and you need much higher levels of nitrate before your plants will see any noticable benefit anyway.

Also, from an infection control PoV sharing water from one tank to another should be avoided where possible. Anything infectious in the 10g would be transferred to the 5g. There could be something in there you arent aware of. From a risk/reward angle im not sure its worth it. Just get fertiliser that will do this for you.

What plants do you have? Some plants are just slow growers.

 

[Bumblebeeatrice]

... from an infection control PoV sharing water from one tank to another should be avoided where possible. Anything infectious in the 10g would be transferred to the 5g. There could be something in there you arent aware of. From a risk/reward angle im not sure its worth it. Just get fertiliser that will do this for you.

What plants do you have? Some plants are just slow growers.

I hadn't thought about it from an infection standpoint, I guess that's definitely something to consider. I have some fertilizer coming in the mail, I'm just being impatient ? a valsinera in my other tank is showing signs of potassium deficiency so I got some root tabs that ill throw in my 5 gallon as well. I think the combined liquid/root fertilization will help my plants,

I have dwarf hairgrass, rotala rotundifolia, s repens, alternanthera reineckii and submerged crystalwort. I know that the rotundifolia is supposed to be a faster grower, but I'm not quite sure about the other ones. The light I have isn't really powerful enough for the repens or reineckii, so it could be a lighting issue as well. I have a longer period of light but don't know if that makes up for poor intensity.

I'm too poor to be an aquarist, but it doesn't stop me from trying

 

[Aiken Drum]

Plants arent an expensive option. I stick with low demand plants. Pretty much any aquarium light will suffice, they dont need much in the way of fertiliser, they dont need specialised substrate, in fact some dont even need substrate. I literally throw away 30% excess growth from my plants every month following leaf removal etc and i do nothing specialist beyond adding a basic liquid fertiliser with water changes and some root tabs twice a year.

If you are going more high demand plants thats a further level.

 

[Bumblebeeatrice]

Plants arent an expensive option. I stick with low demand plants. Pretty much any aquarium light will suffice, they dont need much in the way of fertiliser, they dont need specialised substrate, in fact some dont even need substrate. I literally throw away 30% excess growth from my plants every month following leaf removal etc and i do nothing specialist beyond adding a basic liquid fertiliser with water changes and some root tabs twice a year.

If you are going more high demand plants thats a further level.

We might have a different definition of expensive haha.
Its running off a desk lamp, plants are extras from cuttings/tissue cultures my friend had for his tank (barring the crystalwort and hairgrass). My plants are a touch more high maintenance than wisteria or similar, but not too bad. I saved up to buy a fertilizer that's on its way, and am saving for a proper light next. Might take a few months though.

I think once I figure out the nutrient demands and lighting, the plants won't be too much to maintain. Just troubleshooting right now.

 

[Aiken Drum]

We are on the same page here. A desklamp is probably fine for low demand plants in a small tank. And like i say i throw away clumps of viable plants every month. I have supplied many tanks with java fern from what was once a single plant. A £6 bottle of ferts would probably last a year with small size tanks and you could probably do without. Java fern doesn't even need substrate. I keep saying i could keep java fern alive in a bucket of water in the shed. If you simplify down plants dont need to be a drain on the wallet.