Small (2.3G) Tank pH Blues

[Popeye21]

Hey all. My tap waters is coming out the tap at a consistent 6. With having to increase pH, I'm using API pH Up, for my top off water, I am having a very hard time keeping the tank itself at or close to 7. I am using both strips and API Freshwater Master Test Kit (the kind with vials and drops) to keep track. Any suggestions on how to stabilize things and keep a consistent range. I have a planted tank with a few mystery snails, 1 Nerite snail, 2 Neon Tetras and 4 out of 20 Shrimp left. No breeding. I have a filter and heater so temps are consistent at 71F and the water is clear. I cut b ack on lamp light and added some root tabs to help the plants. And I cut back on feeding as recommended. Everyone swims or crawls, responds to food and generally look healthy. Thoughts?

 

[Aiken Drum]

Is the pH falling or rising?

When you say top off water, do you mean water you use for topping up from evaporation, or water you use for water changes?

What is your carbonate hardness (KH)? Can you give me what this is from the tap, what this is immediately before you normally add the pH up, and what it is immediately after you normally add the pH up.

Whats probably happening is you have low KH. KH keeps pH stable by absorbing acid, this is called buffering. The natural processes that happen in aquariums generally work to acidify water. Fish respiration exhales CO2, which forms carbonic acid, at night plant respiration does the same, the nitrogen cycle turns ammonia into nitrate, which forms nitric acid. Without KH in the water, there is nothing to absorb these acids and pH will drop, sometimes rapidly, and often causing issues with fish.

The pH Up works by increasing KH, increasing the buffering capacity, removing acids from the water and raising pH. Once the KH is used up your pH will go back to falling again.

Lets find out where your KH is though, and if its low you could look at a more stable source of KH, or perhaps you need a more regular schedule of testing your water and dosing pH Up. This is why its not really a good idea to try and adjust water parameters, because its difficult to keep things where you want, when your waters natural tendency is to be somewhere else. Its almost always better to leave your water alone and keep fish etc that suit your water parameters. Especially in such a small volume of water, keeping parameters stable is going to be a task and a half.

 

[Popeye21]

Sorry, should have said. It is always low. I'll adjust it up to close to 7 and then adjust the top off water to help keep it that way, but whenever I test a few days later (when I remember) it's testing lower. Today after a week of not testing it was around 6.

 

[Aiken Drum]

Looking back at one of your old posts, you have a photo of a test strip where both the general and carbonate hardness is showing at zero.

This may not be the same aquarium, but assuming its the same water thats the problem. The pH Up will be adding some KH to the water, but in between water changes thats getting used up and your pH just drops again.

 

[Popeye21]

Ah that makes sense. What should I be doing about it? I've added Shrimp Mineral Rocks (SunGlow), and have NeoTiger KH+/GH+. Will these additions help with the swings in pH? I guess I need to monitor more closely.

 

[Popeye21]

Thanks for the discussion. My KH and GH are both showing 0 from the tap using JNW Direct test strips. I'm trying to keep neocaradina shrimp, ironically because they are supposed to be low maintenance. I did not understand the tap water deficit before I had everything set up, Now I'm playing catch-up each top off. I typically don't do water changes per se.

 

[Aiken Drum]

I've had a look at what these products do.

The SunGlow Shrimp Mineral Rocks are a source of calcium and magnesium, so these will raise general hardness. It doesn't actually mention carbonates or bicarbonates which is what you need to raise carbonate hardness. There is probably carbonate and bicarbonate in the mineral composition (ie calcium carbonate), but as it doesn't say anything about this, I'd work on the presumption it isnt doing much for KH.

NeoTiger KH+/GH+ will obviously increase both KH and GH. It recommends dosing to 6 to 14dGH for shrimp which is about right. When you dose upto that level what does it bring the KH too?

An issue is that KH gets depleted, whereas GH doesn't. KH gets used up by the buffering of acids I mentioned, and its used up in the chemical process of the nitrogen cycle turning ammonia into nitrate. So over time KH will get lower between your dosing the NeoTiger stuff. But the GH doesnt get used the same. A little calcium will go into the formation of the shrimp shells, but generally every time you dose that NeoTiger the GH will get higher and higher and higher, and you arent doing any water changes to bring it back down.

4 options that I see.

Daily monitor parameters and intervene as necessary with the NeoTiger stuff and water changes. Dose NeoTiger when the KH drops below 4dKH. A water change to bring GH down when the NeoTiger dosing pushes GH above say 10dGH. Might be a bit tricky to balance the 2 parameters with 1 product.

Daily monitor parameters, but get rid of the NeoTiger stuff. Change to using salts that you can independently control KH and GH. Seachem Alkaline Buffer will raise KH without touching GH. Seachem Equilbrium will raise GH without touching KH. If one or the other needs raising, you can do that without raising the other. I would still do some water changes. Only topping up from evaporation isnt a good idea.

Stop using tap water. Buy bottled water/ mineral water that suits the parameters you are looking for. Do water changes using the bottled water to ensure the mineral content levels are maintained. Its a small tank, buying a couple of gallons of water per month won't break the bank.

Or, keep things that do well in soft, acidic water. This is the best option, but I suspect its not the route you will take.

I would get a proper test kit. Test strips arent all that accurate, and with your issues you need to be doing a lot of monitoring. Test strips are expensive. A test kit like API Freshwater Master Testkit gives you 100s of tests for the cost of a couple of packs of test strips. And get API GH and KH tests too.