Cycled tank but fish dying

[JoeFinn1997]

Hello,

I’ve completed a fish in cycle (I didn’t realise this was bad due to poor advice from the store). My ammonia and nitrite readings are consistently 0 and my nitrates are kept below 50 with water changes when necessary.

However, it seems I am having more problems with fish health now the tank is cycled than while I was completing the fish in cycle. My fish are hiding a lot of the time, although still eating, and also I have lost two fish who seemed completely fine during the cycle and then went quickly downhill after the cycle.

I am just wondering what I can do to prevent further losses and is there anything further I need to check on the tank.

For reference, my tank is 100 litres and I originally had 8 Livebearers. 4 platy and 4 mollies. I have lost 1 of each fish so far. I only have artificial decorations and no live plantation.

From my understanding, the fish listed above are supposed to be ‘hardy’ fish. Therefore, if my main water parameters(ammonia, nitrite and nitrate) are consistently fine then I have no idea what is causing the issue. I have plenty of surface movement and also an air stone.

Any thoughts/advice would be much appreciated.

Thanks

 

[Naughts]

The nitrates are high - aim for a maximum of 20ppm. Do you know/ can you test for the level of nitrates in the source water?
Platies and mollies need hard water - can you find the hardness of the water that you are using? Water companies usually publish this in the water quality report on their webpage.
What is your water change schedule and maintenance routine?

 

[JoeFinn1997]

The nitrates are high - aim for a maximum of 20ppm. Do you know/ can you test for the level of nitrates in the source water?
Platies and mollies need hard water - can you find the hardness of the water that you are using? Water companies usually publish this in the water quality report on their webpage.
What is your water change schedule and maintenance routine?

I completed a water change this morning and the nitrates are reading as 5ppm as of just before my post.

I think my carbonate hardness is high but my “total hardness” is low. I have struggled with maintaining a high PH and i guess that may tie into the low total hardness?

If so, is there an easy way to increase the hardiness of the tank water and maintain that level?

In terms of water changes, I test the water every 3 days and complete a water change when I read high nitrates. I’ve been fasting the fish for one day a week and only feeding small amounts. I vacuum the fish waste during the water change also.

 

[Naughts]

I completed a water change this morning and the nitrates are reading as 5ppm as of just before my post.

Perfect.

I think my carbonate hardness is high but my “total hardness” is low. I have struggled with maintaining a high PH and i guess that may tie into the low total hardness?

Are you referring to TDS (total dissolved solids) or GH (general hardness)? The GH needs to be around 200 for platies and 250ppm for mollies. Once you know your GH you could add mineral salts if necessary.

Meanwhile, post pictures of the fish and explain any symptoms in case there are other factors at play.

 

[Colin_T]

The easiest way to increase the GH, KH and pH is to add a Rift Lake water conditioner at a lower dose rate. You want the GH around 250ppm for mollies and around 200ppm for platies. Platies will be fine in harder water but mollies won't be ok in softer water so find out what the GH is and get it up to around 250ppm. A Rift Lake water conditioner will also raise the KH and pH. Mollies and platies like the pH above 7.0.

If you post pictures of the fish and 1 showing the entire tank, we might be able to offer more advice on what the problem is.

Naughts beat me to it

 

[TwoTankAmin]

Just as an FYI

Hardening Your Water (Raising GH and/or KH)​

The following measurements are approximate; use a test kit to verify you've achieved the intended results. Note that if your water is extremely soft to begin with (1 degree KH or less), you may get a drastic change in pH as the buffer is added.
To raise both GH and KH simultaneously, add calcium carbonate(CaCO3). 1/2 teaspoon per 100 liters of water will increase both the KH and GH by about 1-2 dH. Alternatively, add some sea shells, coral,limestone, marble chips, etc. to your filter.

To raise the KH without raising the GH, add sodium bicarbonate(NaHCO3), commonly known as baking soda. 1/2 teaspoon per 100 Liters raises the KH by about 1 dH. Sodium bicarbonate drives the pH towards an equilibrium value of 8.2.

Raising and Lowering pH​

One can raise or lower pH by adding chemicals. Because of buffering, however, the process is difficult to get right. Increasing or decreasing the pH (in a stable way) actually involves changing the KH. The most common approach is to add a buffer (in the previous section) whose equilibrium holds the pH at the desired value.
Muriatic (hydrochloric) acid can be used to reduce pH. Note that the exact quantity needed depends on the water's buffering capacity.In effect, you add enough acid to use up all the buffering capacity.Once this has been done, decreasing the pH is easy. However, it should be noted that the resultant lower-pH water has much less KH buffering than it did before, making it more susceptible to pH swings when (for instance)nitrate levels rise. Warning: It goes without saying that acids are VERY dangerous! Do not use this approach unless you know what you are doing, and you should treat the water BEFORE adding it to the aquarium.

Products such as ``pH-Down'' are often based on a phosphoric acid buffer.Phosphoric acid tends to keep the pH at roughly 6.5, depending on how much you use.Unfortunately, use of phosphoric acid has the BIG side effect of raising the phosphate level in your tank, stimulating algae growth. It is difficult to control algae growth in a tank with elevated phosphate levels.The only advantage over hydrochloric acid is that pH will be somewhat better buffered at its lower value.

from https://fins.actwin.com/mirror/begin-chem.html#altering

 

[Essjay]

@JoeFinn1997 The most reliable way to find your hardness, or GH, is by looking on your water company's website. You need a number and the unit of measurement (there are several they could use). If you can't find it, tell us the name of your water company and we'll see if we can find the page.

 

[AJ356]

The nitrates are high - aim for a maximum of 20ppm. Do you know/ can you test for the level of nitrates in the source water?
Platies and mollies need hard water - can you find the hardness of the water that you are using? Water companies usually publish this in the water quality report on their webpage.
What is your water change schedule and maintenance routine?

To say nitrates should be 20 max. What are you basing this on? And for what fish? All fish?

 

[Naughts]

To say nitrates should be 20 max. What are you basing this on? And for what fish? All fish?

High nitrate levels compromise the health and wellbeing of the fish. Their immune system is compromised and it can lead to disease. Nitrates should be kept as low as possible, preferably below 20 (although in the past it was thought that 40 was low enough, it is now thought to have a negative impact above 20). Some fish species are more sensitive than others. Most common causes can be easily controlled by good husbandry.

 

[JoeFinn1997]

@JoeFinn1997 The most reliable way to find your hardness, or GH, is by looking on your water company's website. You need a number and the unit of measurement (there are several they could use). If you can't find it, tell us the name of your water company and we'll see if we can find the page.

United Utilities is the company. If you need further details please let me know.

 

[JoeFinn1997]

United Utilities is the company. If you need further details please let me know.

 

[JoeFinn1997]

The easiest way to increase the GH, KH and pH is to add a Rift Lake water conditioner at a lower dose rate. You want the GH around 250ppm for mollies and around 200ppm for platies. Platies will be fine in harder water but mollies won't be ok in softer water so find out what the GH is and get it up to around 250ppm. A Rift Lake water conditioner will also raise the KH and pH. Mollies and platies like the pH above 7.0.

If you post pictures of the fish and 1 showing the entire tank, we might be able to offer more advice on what the problem is.

Naughts beat me to it

I’ve posted a picture of the fish tank below. I’ve also added details of the water company hardness in this thread as well.

Please let me know if you need any further details.

 

[Essjay]

So your hardness is 5.04 Clark. This unit is not used in fish keeping, it converts to 4 dH and 72 ppm which are used in fish keeping.

You have soft water which is way too low for your fish - Colin gave you the minimum hardness for them

You want the GH around 250ppm for mollies and around 200ppm for platies. Platies will be fine in harder water but mollies won't be ok in softer water so find out what the GH is and get it up to around 250ppm.

When hard water fish are kept in soft water they suffer calcium depletion and the stress of this leads to them becoming sick more easily. Colin also recommended using a Rift Lake conditioner to increase GH and KH to the levels needed by mollies in particular.

 

[JoeFinn1997]

So your hardness is 5.04 Clark. This unit is not used in fish keeping, it converts to 4 dH and 72 ppm which are used in fish keeping.

You have soft water which is way too low for your fish - Colin gave you the minimum hardness for them



When hard water fish are kept in soft water they suffer calcium depletion and the stress of this leads to them becoming sick more easily. Colin also recommended using a Rift Lake conditioner to increase GH and KH to the levels needed by mollies in particular.

Thank you. So it’s the water hardness that could be causing the issues?

If so, I’ve seen the Rift Lake product but I can’t find it in the UK? Is there an alternative as I want to correct this asap

Thanks

 

[Essjay]

A quick search on eBay and Amazon for "rift lake salts" and "cichlid lake salts" produces several products - Seachem Cichlid Lake Salt and Fritz Rift Lake Probiotic. The Seachem product just adds GH so you also need a separate buffer to increase KH. Though I don't know whether you would need their Tanganyika buffer or their Victoria/Malawi buffer - someone else should be able to help there. (Seachem also make an American Cichlid Salt, which is not the right one).

To use these, you would need to dissolve them in the new tank water at a water change before adding it to the tank. You would also need GH and KH testers so you know how much to add to get the level you need for the fish. You wouldn't need to test every time as once you know how much to add to each bucket of water just measure that same amount in future.



The other alternative would be to rehome the remaining fish and have soft water fish in the tank. A shop might be willing to part exchange your fish for soft water fish.