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Advice from the LFS

2K views 13 replies 12 participants last post by  Byron 
#1 ·
Okay, as I had to travel into the "Big City" for business today, I decided to take a detour by the LFS..

I got to talking with one of the employees there as I was looking at the cichlid tank (which is pronounced Sick-lidd not the funky way I said it: chick-lid)

Anywho - he was telling me that because I wasn't breeding fish - that I was changing my water too often and the less that I changed it the lower the pH would get... WHAT??? He suggested a 20% wc every 6 weeks on a 55g tank...

Is this really true?

I can't imagine my little fishies swimming in their own gunk for 6 weeks...
 
#2 ·
Scared.... very scared...

I change 24% of mine every Sunday while I clean the gravel... I left it for two weeks once, BIG MISTAKE. (just a dirty tank... I'm not sure if it negatively affected the fish.)

If there was a fish bible, it would say "Thou shalt change water." And I do, and I think it's a good idea if you do too.
 
#4 ·
Eh, it depends how many fish live in there... if you had one guppy in a 55g tank you probably would rarely need to change it. A normal tank needs that much about every week I'd say.
 
#5 ·
I do water 20% water changes Once a week. My PH is at 8.2 And it never drops after a water change. Or for 2 weeks when i left them for vacation. So you could listen to the LFS or you could get a PH test kit and check your water befor and after. Or read what many of us here do and around the world do.
On acounts to the Cichlids do you have cichlids?
 
#6 ·
Well I think it makes sense that changing less often would lower the PH...

As far as Water changes, I'm not sure. I've heard every opinion, from once every 6 weeks to never. (in a heavily planted tank, that is. Wouldn't apply to tank that wasn't planted.)

Personally, I'd say test the water, and when the nitrates start to appear, change it.
As far as the fishies swimming in their own gunk, it's not really "gunk" after the bacteria get done with it.

I could be wrong, but the main reason anyone changes the water is to get rid of nitrates. Everything else is broken down into other, somewhat useful or inert substances.
 
#10 ·
Most books on care of Tropical fishes, will recommend weekly water change. Would trust published books much more quickly than opinions of nearly all others. Books are normally edited for accuracy and content before publishing.
In my view,frequency and volume of Water changes depends on many factors.Safe play is to change at least 25 percent once a week. IMHO
 
#12 ·
As some one else suggested, there are no "one answer does all" replies. A heavily planted tank with a bio load that isn't to "taxed" isn't going to need changes as much as an empty tank except for the fish. Larger fish will need more changes than smaller fish, if the tank with the smaller fish isn't pushing its "bio load" limit.

Water changes is an area I tend to not trust what I read on the net as the advise is all over the place from no water changes to massive frequent water changes. I have yet to find any "studies" that back up recommendations. I'm more inclined towards "stasis," that is - stable conditions for fish and plants that don't stress them. I'm hesitant to give you any recommendations as I don't know your tank, filtration system, plants, etc. and how "dirty" your fish are (for example, gold fish produce more waste than many tropicals).

Here's a link to a chap I trust the most at present; he has professionally maintained many aquariums, does his own studies and is willing to disagree with the "prevailing opinions."

Aquarium Cleaning; Reasons & Methods, Frequency, Siphon Troubleshooting, more.
 
#13 ·
I guess I was not so concerned about the frequency of water changes as so much as


"You pH will lower naturally if you don't change your water" advice....


** He did suggest that I buy a pH buffer, though so while not pushing frequent water changes buying water conditioner, he was suggesting I buy the buffer... not sure if that was more profit or not as I bought nothing.

Currently I am using driftwood, considering peat, and/or considering fish that thrive in pH 8 water
 
#14 ·
There is some truth in the statement that no water changes will lower your pH, but that is a very dangerous game to play and it risks the health and lives of the fish.

As the biological processes in the aquarium continue, they produce CO2 as do the fish. As the CO2 (carbon dioxide) increases, the pH will begin to lower. Organics will also build up with no water changes, which contributes further to this. At this point, enter the buffering of the water chemistry.

We talk of water hardness, which is the degree of dissolved mineral (calcium and magnesium chiefly) present in the water; tap water sometimes contains high amounts and sometimes not; you can also add calcareous materials (limestone and lava rocks, dolomite, crushed coral) to add calcium and this increases the hardness of the water in the tank. General hardness or GH is the calcium and magnesium measurement, in simple terms; KH is the carbonate hardness value, the amount of carbonates in the water.

If the water has a high degree of carbonate hardness--measured as degrees KH or ppm (parts per million) KH--it acts as a buffer to keep the pH stable. I am not a chemist, and I do not know at what point the buffering capacity of water will be reached, but it does occur. When that happens, the pH which has up to now been buffered and thus stable, can take quite a drop. This is very stressful to many fish, some will be killed outright, others weakened internally.

If the KH is low or non-existent, there is nothing to stop the pH lowering and it will continue to do so. Sometimes we may want this, and sometimes not. In my aquaria for instance, I have mostly wild-caught fish from the Amazon basin and SE Asia. These fish come from waters with very little hardness if any (some measure zero) and quite acidic, as low as 3.5 in some Amazonian streams. My tap water is pH 7 but zero hardness (GH and KH) so in the aquarium, due to the biological processes and fish I mentioned at the start, it drops steadily. In my 70g and 90g I leave it alone and it is at 5. In the 115g I deliberately buffer it with some dolomite in the filter and it remains at 6 (and GH at 2 dGH).

The effect of the regular weekly partial water change is to prevent the pH from falling too low. Not all fish can live in pH of 4 or 5, so this depends upon what fish you have. And if your tap water has some hardness [most does, but not all as in my case] a regular pwc will prevent the pH from dropping too much because it also buffers it. The pwc also reduces nitrates which can build up to toxic levels; though if you have plants this is not likely an issue as the plants use the ammonia/ammonium and nitrates are few or zero.

On the pH buffer, no. This is a chemical that does not belong in an aquarium with live fish. These chemicals may or may not work, depending again upon the hardness of the tap water and the tank water. A much safer method of controlling this is a regular weekly pwc of 50%. If you have live plants, this can be less and many planted tank aquarists do not do water changes this regularly. That's another matter.

If your water is pH 8, it is likely quite hard (though not always). This means the pH is not likely to lower by not changing water, but it will simply becomes worse and worse each day, literally poisioning the fish. Or I should more correctly say, possibly, because here again there is a lot at play. No two tanks are the same biologically. But the point that most of us would agree on, is that not doing a weekly pwc whatever the amount is long-term not going to benefit the fish and is bound to be detrimental in time, even if they may be hardy fish that can "exist" through it for a while.
 
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