Nearly 100% Water Change

[damovts]

Ive only ever done 20-50%, but atm tank as high ammonia

Is it possible to do a 90-100% what change without doing any harm?

 

[adamgreen240]

No not really, you would get rid of too much of the beneficial bacteria and cause a mini cycle.

 

[Tolak]

As long as the replacement water closely matches the tank water you should not have a problem. What you should really do is concentrate your efforts on what is causing the ammonia reading.

***Edit To Add***

Your tank water contains a tiny percentage of nitrifying bacteria. I do daily 80%+ water changes on fry tanks the first week or two, and set up tanks with cycled filters & 100% fresh water when growing out spawns.

Your nitrifying bacteria is in your filter media, not the water.

 

[damovts]

As long as the replacement water closely matches the tank water you should not have a problem. What you should really do is concentrate your efforts on what is causing the ammonia reading.

***Edit To Add***

Your tank water contains a tiny percentage of nitrifying bacteria. I do daily 80%+ water changes on fry tanks the first week or two, and set up tanks with cycled filters & 100% fresh water when growing out spawns.

Your nitrifying bacteria is in your filter media, not the water.

Ok, and to the post above,,, how about a 80% change?

Im gonna out everything except gravel and syphon every peice of gravel to get as muhc dirt out as possible

 

[Tolak]

As long as your pH, hardness, and temperature match closely it should not be a problem. Like I said, finding out the cause will give you the best solution in the long run. What size tank, how many of what species of fish, how long has this tank been running, and what make & model of filter are you using? Also, what are you using to treat the replacement water, and how much are you using?

 

[vonnie06]

hi damovts if you do an 80% water change and syphon every bit of dirt out you are more likely to put the nitrite and amonia higher then what it is ,like someone said above you'll be doing a mini cycle.the best thing is do a 40% water change one day then keep doing 25% water changes after that everyday if you can it will go down just have a little patience also if you are given to much food to your fish then cut down a little better to give small potions 3 or 4 times a day then given big potions.hope this helps i know its annoying it took my tanks amonia to go down a while but eventually it did go down just took a bit time and patience

 

[damovts]

hi damovts if you do an 80% water change and syphon every bit of dirt out you are more likely to put the nitrite and amonia higher then what it is ,like someone said above you'll be doing a mini cycle.the best thing is do a 40% water change one day then keep doing 25% water changes after that everyday if you can it will go down just have a little patience also if you are given to much food to your fish then cut down a little better to give small potions 3 or 4 times a day then given big potions.hope this helps i know its annoying it took my tanks amonia to go down a while but eventually it did go down just took a bit time and patience

I thought the whole point of gravel syphoons was to do that Getting it out of the gravel that is

 

[Tolak]

I sure would like to see some documentation showing that doing large water changes results in cycling problems, or that removing debris from the gravel causes cycling problems. Most of my tanks have no substrate, when debris is removed there is nothing but clean glass.

If this cause ammonia & nitrite spikes I would have hundreds of dead or deformed angel fry, dead breeders, and so on. The few tanks that do have substrate get 50% water changes, with a vac, and experience no problems.

Large water changes, especially with cooler water, are one method used to induce fish to spawn. It is generally accepted that spawning fish are happy with their environment, or they would not be healthy enough to reproduce, nor sense that the environment is right for reproducing.

 

[damovts]

I sure would like to see some documentation showing that doing large water changes results in cycling problems, or that removing debris from the gravel causes cycling problems. Most of my tanks have no substrate, when debris is removed there is nothing but clean glass.

If this cause ammonia & nitrite spikes I would have hundreds of dead or deformed angel fry, dead breeders, and so on. The few tanks that do have substrate get 50% water changes, with a vac, and experience no problems.

Large water changes, especially with cooler water, are one method used to induce fish to spawn. It is generally accepted that spawning fish are happy with their environment, or they would not be healthy enough to reproduce, nor sense that the environment is right for reproducing.

Well i plan out taking out the fish and putting them into a big bucket for 30 mins while i do the whole tank!!

Whatcha reckon? i did 40% water change the other day and alot of crap came up throug the tube when i went through just a small part of the gravel

 

[tenohfive]

Do daily 40% water changes instead of one big one. I'm not suggesting a bigger water change is dangerous - I've just not done more than 50% before, and am currently doing 40% daily changes to deal with a mini cycle.

The stuff thats buried deep in your gravel - don't worry about too much. Pick up anything thats decaying on the surface, and just keep doing daily water changes until the tank sorts itself out.

 

[Tolak]

Do not forget to keep your filter media wet! It would be nice to know what size tank, fish, etc that you are dealing with here.

If you are planning on taking the fish out, and the tank is that filthy, I'm assuming it has been running for some time. Depending on the tank size it could take longer than 30 minutes, I've moved multiple tanks & fish doing fish room remodels, it will take longer than you think. If you have a lot of fish consider adding an airstone to the bucket, low O2 levels will cause a problem. Make sure to cover the bucket as well, a towel works for this, it prevents fish from jumping.

 

[blodhi74]

I agree with Tolak.
I recently got a new aquarium. I matured the filter media in the old tank.
Set up the new aquarium and added 10% of water from the old aquarium. Rest of the water was treated tap water.
No ammonia spikes or dead fish.

 

[rabbut]

With all due respect to the posters surgesting that large waterchanges will caurse a mini-cycle, aren't you overlooking the obvious? The tank is in a mini-cycle already for some reason. Ammonia is very toxic and does lots of damage. If it is raised, the damage of a large waterchange would be insignificat compaired to that of the ammonia, as ammonia can kill in as little quantities as 0.25mg/l (0.25ppm) in the short-tearm, so getting the levels down again is a top priority. Back in my breeding days, I did 80-90% waterchanges almost daily, with no ill effects.

Water contains about 0.01% of the tanks benificial bacteria. another 0.99% resides on the gravel and oaunaments adn the other 99% is in the filter. A large waterchange will not damage exisitng bacterial colonies in any notiable way. If there is lots of rubish in the gravel, that is probibly the caurse of the raised ammonia.

I'd advise you to stick to the origional plan and do the 80-90% waterchange removing as much rubbish as possible. I'd leave the fish and the filter in the water personally, as catching them will put them under even more stress. I would then refill with dechlorinated tap water, taking care to ensure the temperature, pH and hardness are all similar as I fill.

If you are in any doubt as to whom to follow after all this, look at the fish-in cycling threads in the pinned section of "new to the hobby", and the user status of the advisers. To me, a mods advice is usualy of more weight to me than other members, unless lots of members go against what they are saying. Mods were promoted to their status usually because of above-adverage knowlage of the hobby.

All the best
Rabbut

 

[5teady_2012]

I sure would like to see some documentation showing that doing large water changes results in cycling problems, or that removing debris from the gravel causes cycling problems. Most of my tanks have no substrate, when debris is removed there is nothing but clean glass.

If this cause ammonia & nitrite spikes I would have hundreds of dead or deformed angel fry, dead breeders, and so on. The few tanks that do have substrate get 50% water changes, with a vac, and experience no problems.

Large water changes, especially with cooler water, are one method used to induce fish to spawn. It is generally accepted that spawning fish are happy with their environment, or they would not be healthy enough to reproduce, nor sense that the environment is right for reproducing.

I agree with you,

Its the filter that holds most of the bacteria, i use to have to do 80% changes on my betta fry tanks as well and also water changes helps growth of fish.

 

[PRW1988]

No not really, you would get rid of too much of the beneficial bacteria and cause a mini cycle.

not exactly true as like 80% of the bacteria resides in the filter and on the gravel.

I'd reccomend doing say 75% water changes, every 3-4 days until the ammonia loweres.