[Miss_K]

Hello! Newcomer in the hobby here. I would like some advice regarding water hardness.
My tank has been set up for nearly 2 months, and I haven't seen any signs of plants/animals reacting negatively to the low GH of my water (according to the liquid test kit, it's at most 3°dH). I have java fern, anubias and some pothos growing really well, and java moss struggling a bit (I believe it's because the blackwater and shade from taller plants is blocking the light from parts of it. The best lit pieces are doing much better). I added 4 ghost shrimp two or three weeks ago, and since then they molted and had baby shrimp without any problem, which I've learned might happen if they lacked calcium.
Water parameters are as follow:
PH 7.5
GH 3°dH (at most)
NH3 0 ppm
Tank is a 30 cm cube, so it has a bit less than 7 gallons.
I do not add any ferts, nor CO2, and the food has between 8 and 25g of calcium per 1kg of food.
Should I do something to raise the GH? I would like to avoid raising the PH any more than this, as I planned on adding fish that prefer lower PH (I have Catappa leaves in there in a thus far unsuccessful attempt to lower it).
I thought maybe adding some powdered eggshells might do the trick. Another option is using a shrimp-safe fert I've found that has higher amounts of calcium and magnesium. I just don't know if it might create an algae problem, the way it is now plants are growing a lot with very little algae.
Or should I do nothing and just watch it to see if I can get away with this low GH? My GH and PH have been very stable the past month.

 

[Goodwood]

It does seem a little low, but If it ain't broke i would not try and fix it. If you wanted to raise your gh, i would use a gh booster to do this. Gh is a measurement of calcium and magnesium. I would raise you gh slowly with a gh booster over several small water changes.

 

[Miss_K]

It does seem a little low, but If it ain't broke i would not try and fix it. If you wanted to raise your gh, i would use a gh booster to do this. Gh is a measurement of calcium and magnesium. I would raise you gh slowly with a gh booster over several small water changes.

Thanks! I'll read up on that gh booster and keep it in mind in case the low gh ever becomes a problem.

 

[somewhatshocked]

and java moss struggling a bit (I believe it's because the blackwater and shade from taller plants is blocking the light from parts of it.

It's most likely not doing well in areas where there's not great flow. Moss does best in cool water with decent flow. Low lighting is fine.

Flow doesn't have to be constant - there just needs to be some water movement on a somewhat regular basis.

GH 3°dH (at most)

As previously mentioned, that's pretty low. If it were me, I'd aim to double or triple it slowly, over time. But stability is key and since that's what you've focused on, you've had success.

What's your kH? That tends to matter a lot with shrimp. I'm guessing you've got at least a kH of 2?

 

[Miss_K]

It's most likely not doing well in areas where there's not great flow. Moss does best in cool water with decent flow. Low lighting is fine.

Flow doesn't have to be constant - there just needs to be some water movement on a somewhat regular basis.



As previously mentioned, that's pretty low. If it were me, I'd aim to double or triple it slowly, over time. But stability is key and since that's what you've focused on, you've had success.

What's your kH? That tends to matter a lot with shrimp. I'm guessing you've got at least a kH of 2?

Flow is something I did not consider before, but the area with the most brown moss was indeed a low flow area, besides the low light. Makes sense. Now cool water... That's something to look forwards to for next winter, then, as I don't have an aquarium fan. Right now it's around 26°C (78,8°F) without a heater.

I don't have a kH test, so I don't know. I was however planning on taking a water sample for testing in my LFS, so I'll be sure to check that as well. What I know is that the the ph has been bravely resisting at the 7.5 mark (same as my tap water), so there's some buffering there. The two pieces of wood, half coconut shell and two big catappa leaves in the tank made the tank super dark but did nothing to ph.

 

[somewhatshocked]

Right now it's around 26°C (78,8°F) without a heater.

That's still cool enough for most moss. Though, it does thrive in water that's cooler than that.

One thing you could consider is removing the moss from the coconut shell and attaching it to a random, small piece of wood that you just place on top of the substrate. Something that's easy for you to pick up or remove for trimming in the future. Maybe a tiny branch or something. That would likely make a difference because there'll be more water to move through the moss fronds. I do that in a lot of my shrimp tanks and sometimes just use small pieces of lava rock for that purpose, allowing moss to spread out and get a bit longer than most usually maintain it.

Since you have lower lighting, it will naturally tend to grow upward toward the light and will end up looking really nice in a few weeks/months.

On the kH front - if you want to keep shrimp long-term, it's definitely worth picking up a kH test kit when you have the chance. Since you have tap water that's low gH, you could potentially keep tons of sensitive critters that most of us have to use RO/DI in order to protect them. kH depending, of course.

If your pH is staying at 7.5 no matter what you do, then it could be much higher than 2. Not a bad thing. Just good to know.

 

[Miss_K]

That's still cool enough for most moss. Though, it does thrive in water that's cooler than that.

One thing you could consider is removing the moss from the coconut shell and attaching it to a random, small piece of wood that you just place on top of the substrate. Something that's easy for you to pick up or remove for trimming in the future. Maybe a tiny branch or something. That would likely make a difference because there'll be more water to move through the moss fronds. I do that in a lot of my shrimp tanks and sometimes just use small pieces of lava rock for that purpose, allowing moss to spread out and get a bit longer than most usually maintain it.

Since you have lower lighting, it will naturally tend to grow upward toward the light and will end up looking really nice in a few weeks/months.

On the kH front - if you want to keep shrimp long-term, it's definitely worth picking up a kH test kit when you have the chance. Since you have tap water that's low gH, you could potentially keep tons of sensitive critters that most of us have to use RO/DI in order to protect them. kH depending, of course.

If your pH is staying at 7.5 no matter what you do, then it could be much higher than 2. Not a bad thing. Just good to know.

Believe it or not, the moss in the coconut is one of the patches that's been doing better than average. The dead patches I've already removed, and the ones that have barely reacted since being planted are in that dimly lit area in the middle of the tank. But I'd like then to cover the sharp tips of the wood in there, so I'll persist with that location and see if I can increase flow.
The moss attached to a small piece of wood/stone idea is something I was already considering doing, so it's good to know.
I'll get the kh test then. When I was shopping for the tests I prioritized because getting everything all at once was way too expensive, but a single test is ok now.
Which kind of sensitive critters? I'm curious. Usually what I've seen is something such as "this fish prefers soft water, but the ones bred in captivity can withstand harder water".

 

[somewhatshocked]

The moss attached to a small piece of wood/stone idea is something I was already considering doing, so it's good to know.

It really makes keeping moss a lot easier than it would be otherwise. After a few weeks, whatever it's growing on typically gets disguised and it looks really cool. Being able to remove it for quick trims or to place it elsewhere in the tank is a big plus for me in most of my low-tech tanks.

Which kind of sensitive critters? I'm curious. Usually what I've seen is something such as "this fish prefers soft water, but the ones bred in captivity can withstand harder water".

Several varieties of shrimp, some crabs (Micro Crabs are what I'm specifically thinking), some fish that only breed in softer water. I consider it an overall luxury when people have low gH (or kH) and can adjust it to suit their particular needs. Opens up a lot of doors that would otherwise be more expensive - like getting an RO/DI system.

 

[Miss_K]

It really makes keeping moss a lot easier than it would be otherwise. After a few weeks, whatever it's growing on typically gets disguised and it looks really cool. Being able to remove it for quick trims or to place it elsewhere in the tank is a big plus for me in most of my low-tech tanks.



Several varieties of shrimp, some crabs (Micro Crabs are what I'm specifically thinking), some fish that only breed in softer water. I consider it an overall luxury when people have low gH (or kH) and can adjust it to suit their particular needs. Opens up a lot of doors that would otherwise be more expensive - like getting an RO/DI system.

Indeed, during my first attempt at trimming moss underwater with regular scissors, all I wanted was to be able do take it from the tank to reach the hardest parts. I hope it works, moss is one of my favorite plants but also one that I have the hardest time keeping alive, so... fingers crossed.
About the cool critters that need soft water... I've heard of the micro crabs, they're really cool. Isn't it possible to use rainwater collected in low pollution areas instead of the RO/DI water? This is what people that keep carnivorous plants use (if they don't have RO/DI), as those need poor nutrient conditions. Maybe not for a long term setup, but maybe just for breeding.
(Now that I think about it, a half carnivorous plant bog - half blackwater system would make a very interesting paludarium. )