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Need Help! Mysterious Bristlenose Deaths

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I have been keeping fish since 2014 and have never had any major mind-boggling problems until very recently. I am currently keeping three fully grown freshwater angelfish that are approximately four years old, six harlequin rasboras that are almost six years old, four cardinal tetras and three rummy-nose tetras, both only a year or so old. These fish are all fine, eating normally, active and curious of anything inside or outside their tank. I currently have three pieces of driftwood, three aquarium-safe plastic ornaments and one river rock decorating my aquarium. The substrate currently is Fluval Stratum Plant/Shrimp substrate (I plan to plant my aquarium when I have sufficient funds to do so). My tank measurements are L90, W37, H45 cm. I perform water changes every 1-2 weeks depending on the pH and Nitrate levels. My pH usually sits around 7 or 6.8 and I do a water change if it drops lower than that. I have no ammonia or nitrite in my tank, no copper either. My Nitrate levels are currently just below 20ppm. 

My water changes had been almost solely completed with tank water when I first began keeping these fish. When I first kept fish in a smaller tank, I had guppies and a female Bristlenose Catfish. She passed a few months before I moved my fish tank from the Gympie Region to the Sunshine Coast. The only change I made to my fish tank after the move was to swap the river-pebble substrate out for a fine black quartz sand. Since moving to the Coast I have been unable to keep a Bristlenose alive in my tank for more than a few days. All of my other fish mentioned above are fine and healthy, I even had live plants in the tank for two or three months. Because I didn’t want to kill any more catfish, I tried keeping an Apple Snail in my aquarium, which died after two days I have taken a sample of the aquarium water and substrate to the local aquarium shop and they could find nothing amiss with either the substrate or my water and were quite puzzled — as am I — with why my catfish keep mysteriously dying. With the quartz substrate I did notice that two catfish I had tried to bring into the tank (on separate occasions) developed a twitch in their tail shortly before passing away. There are no traces of salt or copper in the water (which was a suspicion of mine originally). 

Two weeks ago I moved to another town within the Sunshine Coast Region (still using town water) and changed the substrate to Fluval Stratum Plant/Shrimp substrate as I want to create an aquascape in my aquarium. My father has his own 8ft fish tank in which he keeps African cichlids, clown loaches and Bristlenose catfish that breed like crazy. I caught an infant catfish from his tank (around two centimetres or so long) to trial in my own tank with the new substrate. I added the catfish four days ago and it had passed sometime this morning. It had none of the symptoms I had previously noticed with other Bristlenoses (no twitching), but I did notice it was breathing quite erratically last night. Otherwise, it was very active — if a bit shy — in the days leading up to it’s passing. Before I added the catfish to my aquarium I performed a water change, then put about 300ml of my aquarium water into the container holding the catfish with my dad’s aquarium water every 15 minutes. I repeated this five times before catching the catfish in a net and putting it in my aquarium. 

The longest I have managed to keep a Bristlenose alive since moving is three or so months, which was after I added activated carbon to my filter as suggested by the aquarium shop owners after taking a water sample there. I am now due to replace the activated carbon. There is an orange/brown algae growing on the surfaces of my aquarium (substrate, driftwood, rocks, ornaments and glass) that grows very quickly despite my constant scrubbing of these surfaces to remove it. 

I really am puzzled as to what is causing my bristlenoses — and snails — to die after only a few days of purchasing and acclimatising them to my tank. Any advice or help would be extremely helpful as I really love keeping bristlenoses and snails! 

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mind boggling ,

as far as the apple snails go i would say the ph may be too acidic for them as they prefer alkali water as acid will destroy their shells

2 cm bristlenose can be hard to keep sometimes

as far as coming from a african tank the ph may have been too great and even over an hour of trying to acclimatise the fish to new ph  

adding 300 ml of water to a bag or bucket that may have only had 300 ml of water in it and could have had a ph of 8 and your water a ph of 7 means first lot of water dropped the ph to about 7.5, doesnt sound like much but its massive , a ph change of 1 is 10 times  more acidic or alkali 

rapid breathing,,,,stress, be it caused by ph change or by toxins in the tank,like ammonia

what are you using to test your water perameters, test strips can be innacurate, so can old  or cheap liquid test kits, i use api test kits

algae , how much light is your tank getting, too much and even sun during the day can and will cause algae blooms  what kelvin rating are your lights, 6 k and there abouts is good for plants but 14 k is good for marine and will cause algae gtowth

what filters are you using, if youre describing brown algae, its not technically an algae, its millions of diatoms clumping together, so a tank with current will give them less chance of clumping and be able to be caught up in your filter, nitrates and phosphates in your tank will cause algae, and although im no expert on specialised substrates  i would imagine theres both in the soil so the plants can feed amd grow

ive always used fine sand and co2 injection to get plants growing , and the proper lights for plants



maybw these guys can throw some light on all of this

if it was green algae in the water i would try phosguard or investing in a uv filter/ light

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Thank you for your reply! 

The bucket that I brought the Catfish home in would have had approximately 1L of my father’s aquarium water in it. I had also always assumed that fish would die straight away with pH shock, and I didn’t notice the heavy/quick breathing until the night before it died. 
I have also tried bringing larger catfish (5cm or more) from my dad’s tank, but they don’t survive either. 

I am using the API test kits to test my water, and they are only three or so years old. As I said earlier, I took a sample of my water to an aquarium shop in Mooloolaba and they could not find any toxins in the water. My Nitrate levels are not too high either. I am also using Seachem Prime to remove the Chlorine and Chloramines from tap water. 

My tank is currently in a room that gets very minimal light. I am currently using an LED light although the brand escapes me. I have been using this since I started with my 3ft tank and before moving to the Sunshine Coast, I never had problems with orange algae. My driftwood had spots of green grass-like algae growing on it, which died not long after I moved to the Coast (I scrubbed my rocks, ornaments and driftwood clean after the green algae died). 

I am currently using the BioPro Canister filter (EF-800) which filters 800L/H. There is only one spot in my tank where the filter outlet doesn’t create a flow, and I have air stones placed in and around that spot to increase current/flow there. I clean out my filter every 6 months and am now due to do so again, I have just been waiting for a not-so-hot day so that I won’t temperature shock the fish when I perform that water change. 

I am honestly at a loss as to why I have had so many problems, and my gut tells me that it’s the town water shift, but no one else has these problems with town water (my father uses town water in his 8.0pH African Cichlid tank and has no brown/orange algae and his Bristlenoses breed like crazy, but he does live in the Gympie Region which would get different town water to the Sunshine Coast. I have tank water available to me where I am now (tank water runs to the showers and toilets, but not to the bathtub. Apparently a tap outside accesses the tank water which I will test today) and am considering swapping back to tank water to see if it makes a difference. 

Thanks again for the advice!

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Very puzzling indeed. What other catfish besides Bristlenoses have you tried? Since the problem seems to affect only bottom feeders, my first thought was the substrate, but you’ve changed that. Next is the food, what have you been feeding them? Bristlenoses are mainly herbivores. PH changes need to be done very slowly to let the fish adapt. As I found out, some fish can be ultra sensitive. As you live in Nambour, you should have no problem using tank water. I’ve never used anything else, as it doesn’t need additives. As for the brown algae, it could be a sign of insufficient light?

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I haven’t tried any other catfish due to finances, Bristlenose are my favourites so it would be a shame if I couldn’t keep them! The only other bottom feeders I’ve had are snails and clown loaches (the clown loaches I kept before moving to the coast when my bn’s were fine in the tank). 

I recently did a waterchange with tank water instead of tap water and discovered that (while cleaning my filter) one of the interior seals were broken. I thought this might have been causing the brown/orange algae buildup but it’s still occurring within the tank. I’ve bought some new test kits and will post their results on here once I get them. 

The fish get a mixture of flake, Tetra sinking pellets, frozen (but defrosted) bloodworm, and the sinking algae wafers. There is also driftwood in my tank that I know bn’s enjoy to nibble on. 

I thought the same regarding the brown algae, as when I first noticed it on the glass it only grew on two thirds of my tank depth, with the remaining third closest to my light clear. 

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Ok, that probably solves the brown algae issue, light that does penetrate is not enough. So if you ever want to grow plants, you might have to upgrade your lights. As to the catfish, if I was you I would buy 2 or 3 bronze Cory and see how they go. They are in my opinion the hardiest of the catfish.

And another thing: don’t obsess testing the water. You’ll get all sorts of alarming results and start to worry trying to fix things. Just observe your fish, they will tell you if something is wrong.(this from one who’s been there, done that :))

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