PWC Procedure Feedback Wanted

[JackSpadesSI]

There has got to be a better way to do PWC's than what I currently do. Please provide feedback on my idea for a new PWC procedure.

Current:
Remove water = siphon out with python.
Add water = fill a 1-gallon jug with tap water (set to temp), add to jug a couple drops of Prime (just enough to wet the bottom of the cap), dump gallon of treated water from jug into tank, repeat jug process until tank is filled.

Proposed:
Remove water = siphon out with python.
Add water = add enough Prime for 30g of water to 30g tank's remaining water, use python (in "reverse" mode) to fill tank with tap water (set to temp).

My main concern with the proposed PWC procedure is the local concentrations of water before it has all mixed together - prior to mixing, there will be over-Prime'd water and there will be untreated water in the tank. Sure, mixing should be rather fast, but I have no idea how fast fish can be harmed by over/under treated water.

That's the reason I had been doing the additions one gallon at a time - I wanted to ensure that all water the fish would encounter was already treated with the correct dose of Prime.

Thanks for your feedback!

 

[severum mama]

Don't worry about it. I've been changing water for 8 years with your proposed method. Just add the Prime while you are filling the tank and you'll be fine. I've seen so many people say that chlorine/chloramine found in tap water will nuke your biofilter/fish/etc. on contact but IME that is completely false.

 

[jetajockey]

Prime can be overdosed without any issue. I agree with severum_mama about the chlorine thing, its all about concentration, a small concentration of chlorinated water is not going to instantly kill the bacteria in the tank.

 

[mfdrookie516]

Prime is safe in levels up to 5x the recommended dosage (maybe more? that's just what Seachem says). If you do a 50% PWC on a 50g tank, you'll have about 25 gallons left in the tank (less, but we'll use that for this). you add 5ml of Prime for that 50g of water volume. That's 2x the dosage in the 25g until you fill it up. Perfectly safe.

 

[JackSpadesSI]

Thanks so far!

I've got some follow-up:

1) What's the reasoning on adding enough Prime for the whole tank when you're only adding 50% untreated water? E.g. my tank is 30 gallons, so on a 50% PWC should I add enough Prime for 30 gallons or 15 gallons? I'm not worried about conserving Prime for cost purposes, so I'll do what's best for the fish.

2) severum mama said to add the Prime while adding the water. Does it have to be done at the same time, or can the Prime be added first before the water is added? Prime-before-water is probably going to be easier, so that I don't have to hold a capful of Prime in one hand and the python in the other while doing a PWC.

 

[jetajockey]

1) I assume its because the prime is rated to work in certain volumes of water. To make sure there is enough concentration in a 50g tank for example, you'd put in enough to treat all 50g's. I've never had an issue just dosing for the amount of water I remove/add back, but my tap water isn't heavily chlorinated either.


2) I dose all of my tanks before I go around and fill them up.

 

[mfdrookie516]

Yeah, and IME, it doesn't hurt if you don't dose prime before either. Most of the time, I add it half way in to filling... or sometimes forget until after the fact. Obviously, I wouldn't wait until afterwards on purpose, but whenever works.

 

[GodFan]

If I dose my tank after I remove the water and before I refill it is that safe?

 

[jetajockey]

If I dose my tank after I remove the water and before I refill it is that safe?

2) I dose all of my tanks before I go around and fill them up.

Here ya go

 

[GodFan]

Here ya go

Oh lol I misunderstood that the first time lol thanks