Are Large Water Changes Killing Fish? Small vs Large Water Changes -
- Thread starter tarheel96
- Start date
Lol, yes, they are. I only have to leave them like that for about a minute or so.
Here are some pictures from my 220 water change today:
I take it down to fin level in the main tank and because of a leaking baffle in my sump, I drain both the middle and last chamber down to just a few inches of water. Then I refill with about half aged heated water and the other half comes straight from the hose. Now that it’s cold I have to supplement the hose with a few 5gal buckets of hot water that I pump in via one of my smaller pumps.
^^^ It’s kind of hard to see from the pictures above but all of my fish are sticking up out of the water. Lol
Also, I forgot to mention that I use Safe with the water change in my 220. A little less than 1/4 tsp each water change.
Also, I forgot to mention that I use Safe with the water change in my 220. A little less than 1/4 tsp each water change.
philipraposo1982
After reading your thread, is sounds like the claim that large volume water changes might be/are in some cases/are harmful to nitrifying bacteria were pretty much based on the use of an HMF which, at the end of the thread, was believed to never have been fully cycled.
Where does that stand now .. do you know? At the time it was 3 months since starting the HMF, and, if he was ordering seachem stability, then I suppose he was still getting readings for ammonia and nitrite.
I don't fully recall the whole thread and maybe I should read it again. But I created a thread regarding water changes and beneficial bacteria. In that thread I pretty much prove that in the case where your source water is suitable, there is no negative impacts to bacteria even at 100% water change.
As far as different filters go, it won't make a difference to the bacteria so long as the media is suitable for growth and conditions are favorable.
Most important thing to understand is this: if after performing a large water change has some kind of negative effect on your fish it's very likely due to the source water and nothing to do with the bacteria in your aquarium.
Also note that even if you completely wiped out the cycled media, it would not cause for an immediate death or reaction from your fish. Ammonia or nitrites are not going to magically spike. It's likely untreated tap water or a huge temp swing or supersaturated gasses or toxins in the source water.
As far as different filters go, it won't make a difference to the bacteria so long as the media is suitable for growth and conditions are favorable.
Most important thing to understand is this: if after performing a large water change has some kind of negative effect on your fish it's very likely due to the source water and nothing to do with the bacteria in your aquarium.
Also note that even if you completely wiped out the cycled media, it would not cause for an immediate death or reaction from your fish. Ammonia or nitrites are not going to magically spike. It's likely untreated tap water or a huge temp swing or supersaturated gasses or toxins in the source water.
As mentioned its all about knowing your source water on an established system...my city water varies from season to season.. so unless you know what your putting in the tank its a crap shoot.. I always keep shelf stocked with Prime and stability in case fish start stressing after XL water change > 75% .. nice thread enjoyed the input.
Many hobbyists don't know or understand their source water parameters, many don't even know what their disinfectant residual levels are from season to season. They blindly follow manufacturers recommendations and take a by guess or by golly approach to treating tap water. This is another reason why some have issues when performing large water changes.
I do the same thing except in my sump. By my GPH pump calculations I can change 80-100% of the water in 12-15 minutes
