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Hello All. Possible Long Post. Tank Issues.


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Again hello all. Hope you are having a decent day/night wherever you're located. I will try to keep this short, so I'm sorry if I leave out any information you deem pertinent. Just ask me and I'll try to respond the best I can. 

I have a 10 gallon tank. It has 8 Mollys, about 30 Cherry shrimp (recently added), 10-12 Ramshorn snails, and 10-12 Malaysian Trumpet snails.

I have had plants in it since the tank started, but I just got another order of plants to add which I did. 

My house is on well water with low PH before off gassing (6.0-6.4), and it is super soft <1 drop for KH. So I ordered the 1lb bag of crushed coral from Aquarium Co-Op. To prep for the shrimp arriving I added about half the bag of crushed coral to the substrate to raise said PH. And it worked for a day or two. It was sitting pretty at 7.2-7.4. So I thought to myself "Self I have this Indian Almond leaf hear that I had to remove from the tank before because it lowered the tanks PH so much that it killed my other shrimp, and it was so low that the test couldn't read it. If I add it now maybe the PH will level out at 7.0 and the world will be perfect. The shrimp will have the almond leaf to eat off of, and the coral will keep the PH in the upper range, and the shrimp will have calcium from the coral to molt correctly everything will be perfect" Well I was WRONG. Even with about half a pound of coral in the tank the PH kept steadily decreasing. Added some more coral to a baggy and put in aquaclear 20 hob to raise PH higher quicker. Nope still didn't do anything. Removed almond leaf and now have all this coral in the tank. I tested the water within the past hour. Here are the numbers. GH-14, KH-1, PH-6.4, Ammonia-0, Nitrite-0-.25ppm, Nitrate- 0-5ppm. The GH is through the roof. I also thought coral helps make the KH, AKA the preverbal "trash can" bigger so it can handle more of a swing. I am hoping that the tank levels back off around 7.2-7.4. Pretty sure everything will die if it reaches in the 8's. Also with the high GH I'm pretty sure the shrimp will get the white circle of death after their next molt.  

If I left anything out let me know. I know people say I shouldnt be chasing the water parameters especially PH and to just leave the tank alone. The last time I did that I lost some fish, and mostly all of my shrimp from a PH crash. So I would appreciate some constructive criticism, instead of "C'est La Vie"

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On 6/4/2022 at 1:31 AM, TimmG said:

My house is on well water with low PH before off gassing (6.0-6.4), and it is super soft <1 drop for KH. So I ordered the 1lb bag of crushed coral from Aquarium Co-Op.

Because you're having a severely low starting PH, you might need 2-3 Lbs of crushed coral to buffer the water. I would highly recommend adding more to the substrate if you can.

I would also recommend having something to manually dose buffering agents during water changes. I have some seachem alkalinity buffer for my use. Others have recommended baking soda.

Thinking about this issue I have two points I'd like to consider. First, are the shrimp losses due to a lack of GH/Calcium in the food or the water? Second, how much KH buffer to you need to raise it to your target.

Let's say you want to go from a dKH of 0 to a dKH of 6-8.  This would give you the ability to have a stable PH. I don't mean it will ensure it, but it gives you the ability to have a stable PH. At this point, you'd be running aragonite substrate or trying to condition water change water by having it in a big container somewhere with a pump head and aragonite. Let's say it takes 1Lb of Crushed coral to get it from 0-->2 dKH. Regardless of whatever that does to PH, it's not enough to get it to your desired result. So your option is time or to add more buffer. So let's say we triple it. The first time you change water it will likely dilute things and then you have to wait for the substrate or HoB to leech out more buffer into the water column. This is where preconditioning the water helps and where adding buffer manually during WC might provide a more stable environment longer term.


I don't know if that helps, but I hope it explains the struggle you're going through.


Your first task is to get the KH where you want it to have a stable tank. Usually this is above 6dKH or 60ppm. For my own tank I'm shooting for 80ppm.  Then you can use PH adjusting chemicals to adjust your PH, or better yet. Add wood for the shrimp.

For reference from ACO:


Crushed coral is a great tool for raising the pH of your water. We use it at 1 pound of crushed coral per 10 gallons of water when mixed in with our gravel. Crushed coral dissolves continuously over time. The lower your pH is, the faster it dissolves. As the pH rises, it slows down how fast the coral dissolves. Crushed coral adds a bit of hardness to the water and it significantly boosts KH which buffers pH from swinging."

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On 6/4/2022 at 2:54 AM, Brian said:

Many years ago I also kept a couple marine aquariums.  Early 80’s….  And I would use a mixture of crushed coral and Dolomite.  Maybe Google Dolomite.

I did, no idea why but:



Dolomite contains varying levels of crystalline silica, which can cause damage to lungs or even cancer when it is breathed in. The material can also cause irritation to the skin and eyes. The Department of Health also attested to dolomite's health risks, especially the adverse reactions in humans when inhaled

It is used for acid neutralization in the chemical industry, in stream restoration projects, and as a soil conditioner. Dolomite is used as a source of magnesia (MgO), a feed additive for livestock, a sintering agent and flux in metal processing, and as an ingredient in the production of glass, bricks, and ceramics.


Edited by nabokovfan87
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My Vampire Crab tank has similar issues.

The critters in the tank deplete KH at an alarming rate, and since it is a bog, acidity is a staple. I use Seachem Alkaline Buffer with every weekly WC to replenish the KH, have a bag of crushed coral in the canister filter, and do a top off in the middle of the week with necessary adjustments.

Any critter that needs to maintain shells will contribute to the depletion of KH. Things were normal in the tank until I got a MTS invasion, but the crabs like to munch on them, so they are staying.

I hope this helps. 🐌

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On 6/4/2022 at 5:29 AM, nabokovfan87 said:

I would also recommend having something to manually dose buffering agents during water changes. I have some seachem alkalinity buffer for my use. Others have recommended baking soda.

I have used baking soda in the past. And while yes it does chemically alter the PH of the water to the more alkaline side of the spectrum, it also shocks my shrimp. EVERY time I have used baking soda I have lost shrimp. Not all of them mind you, but 1-3 die within a minute or two of adding baking soda. And with a colony of less than 30 now I cant be losing two or three every time I need to buffer the water. I woke up this morning and my shrimp were going crazy. As in swimming all around the tank. I tested the PH and it was BRIGHT yellow. So low the test couldn't even read it. For my master test kit that is well below a PH of 6. So I hurried up and dosed 1/4tsp of baking soda knowing full well what was about to happen. After I did that they all calmed down except for 1 that I can see is belly up. I did a water change (2 gallons out, 2 gallons in, 2 gallons out, 2 gallons in, and once more 2 gallons out, and 2 gallons in. Also per your suggestion I added the rest of the crushed coral to the baggie in the HOB the AC20 is so small that it barely fits the sponge, bacteria blocks, and the crushed coral. Had to remove the fine filter mesh from the top of  the stack. I know I can just add it to substrate, but I needed quicker results. If everything keeps going well I will remove it from HOB filter and put into substrate. Right now due to the combination of water changes, baking soda, extra crushed coral in the filter I have a GH of 9 (down from 14 last night), KH of 3 (up from 1 last night), PH of 6.4-6.6 (about the same as last night). the other three are 0's after the water change. Still lost a little shrimp though. Always sad. 

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On 6/4/2022 at 1:08 PM, nabokovfan87 said:

Maybe Flip Aquatics has a video on this issue? I'll have to research. They have don't videos on shrimp specific items but I don't know if any are designed around buffering the KH specifically.

Maybe the shrimp king has something also.

Ill look into it on youtube.

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My water is fairly neutral out of the tap but super soft, usually zero or one dkh. I've never had much luck with crushed coral - I don't know if I wasn't adding enough or what. Adding a little Seachem Alkalinity with water changes has worked well for me. Also, someone who's better at water chemistry than me should chime in if I'm wrong, but what about using hardscape that raises ph? I have seiryu stone in my shrimp tank and it has raised the ph quite a bit.

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I would recommend slowing down and not chasing "perfect" 7.0 is not perfect for any species. Stable water parameters are much more desired. The biggest thing that moves the needle here is probably the food going into the tank. 8 mollies could be a lot. If they are adults and you feed them till full, that may overwhelm the tank.

A heavy bioload mixed with low ph tapwater is always going to be a struggle. It's essentially like spending more than you make, you'll always be in debt. Crushed coral is like a savings account.  It'll add buffer that will grow over time but it's slow. If you spend more than you make, you'll run out of savings and go into debt. That is where you are now. The trick is going to be managing the load.


You could have a container of water with crushed coral ready for water changes to bring ph 7+ water in instead of low ph Water. That would help. You could reduce the amount of food you feed, perhaps feeding a higher quality. Lastly you could reduce the amount of animals in the 10 gallon or expand to a larger tank size.


Finally be aware that as the mollies get larger, in a 10 gallon with shrimp, It's likely their appetite will make them prey on the shrimps. They may not directly eat them but they may cause quite a bit of stress.

Just talk calm steps and realize that all water parameters are essentially a math problem and working through the problem slowly to understand the parts, will give you the best chance at the desired result you're looking for.

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