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No R.O. water and buffers


Jan 20, 2003
I don't have a RO unit right now, so I plan on just using tap water that will be purified via a solution like Aqua plus or the like. I know RO is the best, but I can't afford it right now. Will this stuff work like it says it will? Also, will I have to add any kind of buffer to the tank before I mix the salt? I want to make sure everything it completely perfect before I start introducing an octopus.

set up the tank as if it was a reef tank, so if you make up soem water and it needs buffer then do it, but its hard to say without knowing what your tap water is like... they are all different...

Perhaps you could buy RO water from your LFS?? Its not expensive.. Nancy does that, she may be able to tell you how much it was?

You want to give the octo the best possible chance so try speaking to a LFS and get them to test your tap water for copper and nitrates etc..


Yes, I have been buying RO/DI water, and I've found many places to buy it not far from my home: aquarium stores and grocery stores.
Certain grocery stores here in Dallas sell RO/DI water as drinking water for $.29/gallon and the aquarium stores sell it (buffered) for $ .39/gallon.
If you need to fill a whole tank, the aquarium stores will usually lend you the 5-gallon plastic jugs for the water.

One of my LFSs sells R.O. water for $.99 a gallon. So when I want to fill up my tank, it's going to be $75.00 just for water! This aqua plus says that it removes heavy metals heavy metals from the water, as well as clorine and cloramine. Should I trust this stuff to do what it says?
Is any of the bottled water (purified, spring, distilled) from grocery stores comparable to RO or DI water. I volunteer at an aquarium (the North Carolina Aquarium), they make DI but I doubt they would give it to me. The closest fish store that I know of that sells it is 5 hours away near my parents' house. I don't mind hauling buckets of it back but would rather get it from somewhere closer.

Hi John,

Why don't you ask the NC Aquarium first - the water is cheap to produce and they probably make up quite a quantity. We've had other community members report getting such water at no cost from university labs.

If that doesn't work, check what is meant by the "purified water" available for purchase, even if you have to contact the company that produces and bottles the water. This probably is RO/DI water, and if so, would be fine for making salt water for your aquarium.

Hope that helps,
I may have a cheap and effective answer for you, a filter you can build for yourself for dirt cheap, under $30, and really more like under $20. A Molecular Absorption filter (kind of like carbon, but broader in capability) using PolyFilter media.

I can't swear to you this will work 100%. So if you try this and kill your octo, please don't kill me! :shock: :cry: :P Just because my octo and other critters are very happy with this system does NOT mean yours will be...you may have stuff in your water this system can't remove. I've had great difficulty finding precise, comprehensive information on exactly what this system removes and what it doesn't, and how often it needs recharging. There's no question it removes a LOT of stuff, but it's also pretty clear it doesn't remove as much as a good (expensive) combination RO/DI system.

That said...here's what I did. Using some DIY information culled from the web, I assembled a filter using PolyBioMarine's PolyFilter material. PolyFilter is pretty neat. Many aquarists swear by it...it's great to have on hand to throw into a tank for emergencies to suck up bad stuff, especially in emergencies when something toxic in the water is suspected. My current "fire drill" plan is to toss one of these in the tank, do a major water change, and add carbon to my canister filter...prolly in that order.

Below I have listed links to all the information I could cull about this media. It's very simple...cut the pipe, drill the holes, roll up the media and insert it, and you're done. I run my water through a faucet-mounted PUR filter (which is basically a carbon filter with some mechanical filtration too) before I put it into this filter. I discovered some problems while doing this...my filter was a bit awkward with the sinks I have access to. Since you'd probably buy a large amount of cheap PVC pipe anyway, I might suggest you construct a "prototype" out of the pipe first and see if you can perfect your design so it's easy to fit into a sink while still allowing the vinyl tubing room to drain properly into a bucket. It also took a few uses before the rolled-up media fully expanded to fill all the gaps in the tube.

With this simple do-it-yourself PVC tap water filter you can achieve about the same results as with a more costly commerical TWP (Tap Water Purifier).

Here's How:
Cut a desired length of 2 & 1/2 inch PVC pipe.
Drill a hole in the center of the end cap, of a suitable size to match the vinyl hose diameter for insertion or attachment.
Attach the end cap to one end of the PVC pipe.
Attach a desired length of the vinyl hose to the drilled hole in the end cap.
Roll up a piece of Poly-Bio-Marine Inc.'s Poly Filter material and place it inside the PVC pipe and add the carbon.
Simply pour or run tap water down through the open end of the PVC filter and direct the treated water that comes out of the vinyl hose to your tank or storage container.
100% silicone sealant can be used to seal the vinyl hose and end cap connection.

Here's the main reason I ascribe some faith in this filter...a review of a commercial water filter that is made using this media. It appears it's often used in hospitals. It seems impossible to find now, but it's easy enough to copy using the above instructions! Note...this media comes in two forms, the sheet form that's discussed in the above directions, and a disc form which the commercial filter is designed for. Some suggestions are that the discs are stronger than the sheets...so if you want to try those, I don't think it can hurt.

The 6 Best Phosphate Removing Products For Fish Tanks, According to a Veterinarian

A review of the media itself:

How to Use Canister Filters in Saltwater Aquariums

Another reference to the use of it as a filter (he's talking about it as part of a really complicated system, but it's good on its own as well.)


If you have bad water in your area, I'd be really nervous about using this, since I can't be sure exactly what it can and can't remove. Otherwise...it might be risky, but it's worked for me and others, and the price is undeniably nice.

I guess the first thing to do is ask the Aquarium if I could get some of their water. Afterall, they do love me and I do work for free! If that doesn't work then I'll either make the trip to my not-so-local fishstore or check into the purified water. Another question, has any body ever used sea water? I live 5 minutes from the ocean. Or would their just be too many unknowns when dealing with ocean water? Thanks, John
Hi rusty

got any pics of your filter??? Maybe worth making it into an article on the site if you are interested?

Sure, I wouldn't mind doing that. I'd research a bit more too to see what other detailed info I could find on it. For instance, I know for sure that I found a site saying you could "recharge" the filter (get it to release most of the pollutants it's absorbed) by soaking/thoroughly rinsing it in the opposite type of water that you typically filter through it...so, if it's a freshwater filter, as mine is, you'd run saltwater through it. Anyway...yeah, that might work out nicely.

john, sorry i missed it earlier but sea water can work but only if you can collect it from an area with no pollution, sometimes excessive spikes will be obatined on ammonia test kits due to planktonic die off etc.

synthetic sea salt is always the safer option :smile:

wow, i guess i got lucky, the aquarium stores around here charge 50 cent per gallon of saltwater with correct salinity, ph and evrything, and the grocery sells RO for about $1.50 for 5 gallons.

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