large water changes and parametric stability

[MrMuggles]

A lot of aquarists drain 50% of the tank water, and then add 50% with dechlorinator and GH additives.

I personally don't do this, instead I fill a reservoir with tap water and treat it with dechlorinator, Equilibrium, and aerate for at least 30 minutes. This treated fresh water is then fed into the inlet of my sump while draining at the same rate from the mid-bottom of the main tank with a siphon.

I do this for a few reasons:
1. there's no stress for the fish from the "oh my god the water is disappearing" feeling they get. I also noticed they hate when the pump is turned off - currents changing/stopping in the tank
2. a professional custom aquarium builder told me that partially draining/filling my frame-less tank often will age the seams faster as it causes them stress.
3. CO2 is injected in the second to last sump compartment so this fresh incoming water is mixed with a bit of CO2 before entering the tank
4. i believe the water parameters (CO2, GH and pH) will swing less wildly with this approach, and I purport that is better for both fish and plants


I know this has a drawback of siphoning out some percentage of the incoming fresh water, but I mitigate this by pumping the fresh water into the sump's first compartment, so it queues a bit and takes longer to reach the main tank.

I'm curious what you all think of my 4th postulate above?

 

[GreggZ]

4. i believe the water parameters (CO2, GH and pH) will swing less wildly with this approach, and I purport that is better for both fish and plants

Nope not all all. There is no such thing as too large of a water change.

Many people change more like 70% to 90% at a time. Nothing really to it. You just add back in the nutrients that you remove.

As to pH if the incoming dKH is the same as the outgoing then there is no change. Sure if you change water during the CO2 period the Co2 ppm will go down and pH will temporarily rise, but it should all be back to regular levels in hour or so. This is of no concern at all.

In general the more large water changes the better. Both plants and fish love it.

 

[MrMuggles]

As to pH if the incoming dKH is the same as the outgoing then there is no change.

Recently I removed the crushed coral from my sump, so this is increasingly true for me now.

 

[GreggZ]

Recently I removed the crushed coral from my sump, so this is increasingly true for me now.

Yep crushed coral brings in a wild card. You really don't want your dKH jumping around like that. Also makes it more difficult to fine tune CO2 injection. I can't think of a tank that would need it or that it would help.

 

[ayman.roshdy]

The last time I added water and dechlorinator directly to the tank caused me to lose 50% of the tank's fish
Since then I stopped doing this and instead add the water, dechlorinator and any additives to an external container and slowly fill the tank after draining 50 - 70% of the water, it should be the same effect as you do currently through the sump but since I don't have a sump then this is the only way to keep everything right

 

[JPog]

The last time I added water and dechlorinator directly to the tank caused me to lose 50% of the tank's fish
Since then I stopped doing this and instead add the water, dechlorinator and any additives to an external container and slowly fill the tank after draining 50 - 70% of the water, it should be the same effect as you do currently through the sump but since I don't have a sump then this is the only way to keep everything right

Do you know what went wrong? On larger tanks I think most (I know I did) run the python right into the tank and dose chlorinater as it's running. With this method you would dose chlorinater for the entire tank volume as opposed to using a separate container and dosing for the volume of water you're changing.

 

[ayman.roshdy]

Do you know what went wrong? On larger tanks I think most (I know I did) run the python right into the tank and dose chlorinater as it's running. With this method you would dose chlorinater for the entire tank volume as opposed to using a separate container and dosing for the volume of water you're changing.

Probably an excess chlorine added to the tap water by the water company without us knowing so the local dechlorinator that I was using was not effective, started to be effective after I started pouring the whole decholorinator bottle into the tank and this saved the rest of the fish, since then and plus using an external container I replaced the local brand and bought Seachem Safe instead

 

[Immortal1]

Probably an excess chlorine added to the tap water by the water company without us knowing so the local dechlorinator that I was using was not effective, started to be effective after I started pouring the whole decholorinator bottle into the tank and this saved the rest of the fish, since then and plus using an external container I replaced the local brand and bought Seachem Safe instead

When I was still using tap water I did basically the same thing right from the beginning - tap water of similar temp into a (at the time) 20g tank. Then added Prime dechlorinator, turned on the circulation pump/fan and let it sit while I drained roughly 20 gallons from the aquarium.
Then pumped the treated water up into the aquarium. Seemed to work well without loosing any fish (specifically to the water change process).

I was initially amazed at how often the local water company would randomly add additional chloramine or other chemicals to the tap water.

 

[MrMuggles]

I was initially amazed at how often the local water company would randomly add additional chloramine or other chemicals to the tap water.

I learned that our local water in Portland, OR was coming from different sources at different times of day last fall. Sometimes there was a very strong chloramine smell, others not.

 

[Art]

So before I switched to RODI, I used good old Miami tap that was surprisingly good for planted aquariums. The problem was that they added plenty of chloramines to the water. While some of the dechloronators say they also remove chloramines, I had a couple of episodes that led me to believe that it wasn't true.

I decided to use a double carbon filter after seeing the Aquarium Design Group boys do this. It simply is a two canister filter filled with carbon blocks.



You can connect your Python to it if that is what you use. I would recommend these carbon block filters: Good carbon block filters.