Rainwater Appears To Be Killing Fish ? Any Ideas?

Discussion in 'Aquarium Water' started by Freshwaterfishkeeper, Apr 7, 2017.

  1. Freshwaterfishkeeper Valued Member Member

    I've had alot of recent deaths. Tank has been setup for about 4 months, it is fully cycled using ammonia method. Water changes are 50% every week in increments of 25%.
    Parameters are:
    Ammonia: 0
    Gh/Kh: not known

    Stocking: 4 harliquin rasboras
    2 albino corydoras
    2 peppered corydoras

    Deaths: 4 harliquin rasboras
    3 albino corydoras
    4 peppered corydoras

    Rough timeline of deaths:
    2 fish one week after I added the new fish
    2 the week after
    3 early the next week
    1 2 weeks later
    1 2 weeks after that
    And 1 a few days ago

    Everything was going fine for about 2 months, then I added non quarantined fish (bad I know, but damage is already done, will quarantine in future). One of these fish had half it's tail missing and some of the other corydoras started loosing their tails too so I treated for fin rot (melafix) it did nothing at all. The rasboras and some corydoras died with no fins missing and no obvious sign of other disease. The fins on the corydoras weren't bad to the point of them dying of that. Every fish that has died has been acting odd, heavy breathing, rapid swimming then died within 24hours of that except 1 (who I cloved) that was on the bottom of tank emaciated and his spine all twisted he was acting wierd for 3 days before he went to the bottom and his spine twisted in about 3 hours I cloved him after that.

    I had another tank (fully cycled with same parameters) with a veil tail betta. I made sure not to cross contaminate anything between tanks he also started loosing fins and then within 3 days was dead (he had clamped fins when I got him which appeared to be getting better with the warm water. He had been in that tank for about 2 weeks.

    I'm thinking water just because of the same kind of death in my betta tank and the medication not working and not all fish being affected at this point. I have added carbon to the tank to try to filter out anything I could I've had 1 death since then.
    I have no way of using any other water as I am in the middle of nowhere.

    If you have any ideas at all on what it could be please let me know, ive been toying with the idea of it being columnaris.

  2. Dragones5150918 Well Known Member Member

    There is a strain of colomnunaris that is fast moving.

    I'm thinking the fish immune system might of been all ready compromised due to the use of rain water. Rain water is like RO water, it has no KH or GH in it, so depending on how much you use, if you remineralize it with either replenish or use something like coral or Limestone, the fish could be suffering in the osmotic process and allowed the bacteria to set in and move fast. The symptoms of rapid breathing and erratic fast swimming point to osmotic and stress.

    I suggest you check your GH, and if your ph fluctuates your KH. In the meantime, I suggest a couple of rounds of Kanaplex, since dirty water does not appear to be the issue.

  3. Freshwaterfishkeeper Valued Member Member

    The ph in my tank does seem to be fluctuating alot i checked it last week it was 8.6 today its 7.4 and I havent done a water change in that time. Im using 100% rainwater im getting a gh/kh test kit I have a readily available source of limestone in my backyard, how would I know if its safe and how much to use, ive also looked into using a kh and ph neutraliser but I would rather use natural methods if I can, how would I go about getting kh/gh into my water ?

  4. NavigatorBlack Fishlore VIP Member

    Rainwater should be neutral - 0 ppm minerals and a pH of 7. I used it in my old house, and it always read as such.
    Neutral pure water will kill most fish. What you have would be happiest in a pH around 6.5, with around 50-80ppm of hardness.
    I always mixed it with tapwater to get the desired hardness. If you have limestone in your yard, then I assume your drinking water will be mineral rich. So you have a cheap, convenient source. of minerals to balance out the water neatly.
  5. Dragones5150918 Well Known Member Member

    If it's limestone in your back yard, just boil a chunk for 20 minutes to kill any bacteria, and toss into your tank. As your ph fluctuates and drops, the limestone will slowly erode and release gh and kh. If any pesticides or fertilizers are used in your back yard, boil longer.

    For a 10 gallon a small river stone size will work. 20 to 50 gallons a large river size stone. Above 50 gallons 2 large river size one on each side of the tank.
  6. Freshwaterfishkeeper Valued Member Member

    So if I add the limestone it should raise hardness kh and intern balance ph ? Is it safe to assume that if my ph balances out that my gh/kh are fine or should I go ahead and buy a test kit anyway ? Also what to do about water changes ? Should I do more frequent with less taken out or use a remineraliser on the water going back into the tank? And treat with Kanaplex for the columnaris.
  7. Dragones5150918 Well Known Member Member

    Yes, the limestone will balance KH and pH. Kh controls the ph, and with out kh, the ph fluctuates and falls, and eventually kills your cycle. It also will slowly raise your gh for the fish osmotic process.

    Yes, still get the test kit. Since your using rain water, you need to know where your kh and gh are at so you know how much you can change with out remineralizing it. Say you get your kh to 5dKH or about 100ppm. If you change out 25% of your water, your kh falls to 4dKH or 75ppm. Same with your gh. Now say you have way to much nitrate and need to change out 50%, you would then need to remineralize the water using replenish and Alkline Buffer. So knowing right where you stand helps with water changes.

    Yes treat with Kanaplex, but after you get the limestone in.
  8. Freshwaterfishkeeper Valued Member Member

    Ok :) thankyou so much, you're the only one whos been able to give me some answers on this
  9. NavigatorBlack Fishlore VIP Member

    I would be cautious, as the effect of limestone was never immediate here. That's why I suggested cutting with tap instead. You don't want to create a situation where every water change drops the hardness radically, to have the limestone bring it up 24 or 48 hours later. A roller coaster of water conditions is not good for the fish.
    Stocking: 4 harliquin rasboras
    2 albino corydoras
    2 peppered corydoras

    You like softwater fish I would not keep in limestone water. It can get too hard. Harlequins are peat swamp fish, from a pH below 7 and with tannin staining of their natural waters. The Corys you have come from faster moving streams, but not ones with a high mineral content or a high pH (also below 7 in nature). So you risk making your water less than ideal for the fish.
    It is hard to strike a balance.
  10. Freshwaterfishkeeper Valued Member Member

    I unfortunately cant get in any tap water for my tank so it will be a bit trial and error with the limestone i will keep a very close eye on the gh/ph and take the limestone out when necessary I can also fill a tub with water and soak with limestone before water change day or mineralise the water I put in as needed. If wost comes to worst i will change my stocking to something more like cichlids and try some crushed coral
  11. chromedome52 Fishlore VIP Member

    First, IME Melafix is a good way to kill fish with fin rot. Not sure what it does work on, but IME all it does is speed the death of fish with actual fungus on them.

    Second, you don't mention how (or even if) you are prefiltering the rainwater. You cannot simply put collected rain into the aquarium. Even in the most remote areas, rain forms around dust particles, and it picks up the most minute pollutants in this manner. When I used rainwater, it was kept in a 55 gallon plastic drum and peat filtered at least 24 hours before using. I peat filtered because I was breeding blackwater fish, but if you don't use peat, you need to use carbon. Once it's in the tank is too late.
  12. Freshwaterfishkeeper Valued Member Member

    I havent used melafix since that one time but i wont use it again. It's only filtered with the tank filter, not sure whats in that filter i imagine not a whole bunch. I will try to find a big drum to filter with carbon before adding. Would running the water through carbon once be enough because I could run it through carbon straight out of tap or would it need to pass through several times ?
  13. chromedome52 Fishlore VIP Member

    It might need to run through it a few times to get everything. You could put a canister or HOB filter filled with carbon on a bucket and run it for a few hours I would think. Aeration of the water is also needed to prepare rainwater for use.
  14. The Senator Valued Member Member

    I'm interested in better understanding the use of rainwater (for a group of apistios).

    After collecting the water and filtering it through the peat did you do anything else before adding it to the tank?

    How did adding the peat filtered rainwater impact the water in the aquarium?

    Did the peat lower the ph of the rainwater?
    Last edited: Apr 7, 2017
  15. chromedome52 Fishlore VIP Member

    1. No, I didn't add anything to the water. The fish I was working with were true blackwater species; most Apistos in the hobby aren't. I was working with very unusual Killifish, Tetras, Gouramis, some West African Cichlids, and a couple of super blackwater Apistos. These were the exceptions that come from water with zero minerals, but lots of humic acids. Basically, the same as the Rio Negro.

    2. I didn't just add the water to a tank, I filled tanks with that water. Generally, it was relatively short term for breeding purposes, but those species that required maintenance in such water (i.e., Paracheirodon simulans) simply had tanks set up with that water, and the same prepared water was used for water changes.

    3. My rainwater, filtered without peat, had a pH around 5.5-6.0. (Lake Michigan evaporation forming on Chicago pollution.) After peat filtering, that could be brought to 4.5-5.0. That was using "regular" bulk peat. Since I started using RO, I tried just soaking it with Sphagnum Moss, and after a week that takes the pH down to 3.5. Believe it or not, there are fish that breed at that level, but generally I cut that with untreated RO to get the pH up around 5.0.