Water changes on a 20 gal

I'm used to my five gallon water changes. A 75 percent water change on a 5 gallon isn't a hard deal. I just vacuum/siphon into a huge 5 gallon stock pot dump the water and refill with correct temp water and add my additives (conditioner, ferts), and I siphon back in.
I'm gonna siphon the water back into my 20 gallon with the same stock pot for water changes as well so my main question is as I siphon each five gallon pot of water should I treat it with a few drops of prime etc or just get all the water in the and then treat all at once? I think I already know the answer to this question haha (treat before adding). But I'm 4'11 and weigh 90ish pounds so five gallons at a time is, I think, max lift haha. And treating 3 seperate pots of water kind of sucks
What do you guys think?? What's you technique.

 

Not sure how sensitive your fish are, but when I do 50% WC's on my 55g, I use the dosage for the full tank (use enough Prime to treat the whole tank). I put 1/2 in before the new water and drip the other half in while the water is filling up. Haven't had any problems for the past 2 years with my cherry barbs, platies, and pearl gourami ¯\_(ツ)_/¯
That being said, I use one of these bad boys that goes directly from faucet to tank, so I don't really have a choice in the matter! I think you can also DIY one with materials from a hardware store, but perhaps look into something like the Python water changer - lugging multiple tubs of water around gets old real fast.

 

Definitely treat before adding. Also, a 75% water change every week is unnecessary. Test your nitrates prior to changing the tank water. If they're really low, don't bother changing that week. If they're not realy low, but well within fish tolerances, do a 25%. Do a 50% if they're higher than that. You only really need to do a 75% if they're outside tolerances for your fish. I'd give you exact numbers, but I have no idea what you keep in there, so I don’t know what their tolerances are.

Note: my water change bucket is 2 gallons, and I've got a 40. I treat before adding.

 

+1 on 75% being excessive IMO. I think the stress on your livestock on that big of a change is more harmful than the benefits of the new water.
I have a moderately planted 20 gallon tank where the nitrates never seem to get over 10ppm. I usually do a 25% water change every 2-3 weeks so I can clean out the filter sponges. When I do change water I treat the new water with dechlorinator before adding it to the tank.
Of course every situation is different, so if your nitrates are higher, your water change routine should be more.
But i'm lazy & don't feel I should change water if I don't really have to...

 

My technique is to get a pump and tubing and pump the water back in. No lifting required

 

Definitely treat before adding. Also, a 75% water change every week is unnecessary. Test your nitrates prior to changing the tank water. If they're really low, don't bother changing that week. If they're not realy low, but well within fish tolerances, do a 25%. Do a 50% if they're higher than that. You only really need to do a 75% if they're outside tolerances for your fish. I'd give you exact numbers, but I have no idea what you keep in there, so I don’t know what their tolerances are.

Note: my water change bucket is 2 gallons, and I've got a 40. I treat before adding.

Ok that makes enough sense too. I have been keeping up on my bettas since his fins ripped and I've been trying to heal him up with clean water so I'm used to excessively doing WCs.
The fish I plan on in this tank will ultimately be guppies, shrimps and Cory catfish. Starting with a school of guppies.

Not sure how sensitive your fish are, but when I do 50% WC's on my 55g, I use the dosage for the full tank (use enough Prime to treat the whole tank). I put 1/2 in before the new water and drip the other half in while the water is filling up. Haven't had any problems for the past 2 years with my cherry barbs, platies, and pearl gourami ¯\_(ツ)_/¯
That being said, I use one of these bad boys that goes directly from faucet to tank, so I don't really have a choice in the matter! I think you can also DIY one with materials from a hardware store, but perhaps look into something like the Python water changer - lugging multiple tubs of water around gets old real fast.

Thank you for the ideas!. I'll check out the python method. My tank is by my front door so the nearest water source would be the house but that's freezing.

+1 on 75% being excessive IMO. I think the stress on your livestock on that big of a change is more harmful than the benefits of the new water.
I have a moderately planted 20 gallon tank where the nitrates never seem to get over 10ppm. I usually do a 25% water change every 2-3 weeks so I can clean out the filter sponges. When I do change water I treat the new water with dechlorinator before adding it to the tank.
Of course every situation is different, so if your nitrates are higher, your water change routine should be more.
But i'm lazy & don't feel I should change water if I don't really have to...

I like your style for sure!
I think it's because my 5 gallon may be over stocked (a betta and 2 ghost shrimp) plus I'm trying to heal damaged fins so I find myself doing water changes often and expected the same with a 20 gallon. Thank you! This will be my biggest tank yet and my second haha.

My technique is to get a pump and tubing and pump the water back in. No lifting required

A pump.. I'll look into that for sure . Makes sense.

 

I am not a heavyweight neither, but that does not really have any influence on treatment. I personally prefer to separate output and input containers, and use the 5gl buckets to drain.
I have 2gl buckets for the clean water, so that us just the right amount to lift. 0.2cc Prime per bucket during filling before it goes into the tank, done.
I can understand your WC schedule, am in the same boat with my Betta. Clean water is essential for those guys and his health is worth it, though 30-50% is working well.

 

I am not a heavyweight neither, but that does not really have any influence on treatment. I personally prefer to separate output and input containers, and use the 5gl buckets to drain.
I have 2gl buckets for the clean water, so that us just the right amount to lift. 0.2cc Prime per bucket during filling before it goes into the tank, done.
I can understand your WC schedule, am in the same boat with my Betta. Clean water is essential for those guys and his health is worth it, though 30-50% is working well.

I never even thought about using seperate containers for input and output but that makes sense too! So at 2 gallons you just, gently as possible, pour it into your tank right?
And 2 cc per 2 gallons, are you using prime too?

 

I never even thought about using seperate containers for input and output but that makes sense too! So at 2 gallons you just, gently as possible, pour it into your tank right?
And 2 cc per 2 gallons, are you using prime too?

2cc is too much. I have a 1ml syringe and use 0.2ml for

2cc is too much. I have a 1ml syringe and use 0.2ml for

Sorry, that went out prematurely. Prime is highly concentrated with 5ml for 50gl.
That makes 0.2ml for a 2gl bucket.
I have a 1ml syringe and it is easy o measure that way.