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Water changes, HMA Filters and dechlorinators . . .

Wookii

Wookii

Moderator/Committee Member
UKAPS Team
Joined
13 Nov 2019
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4,474
Location
Nottingham
I currently have an automated water change set up that uses timers and solenoids to fill a header tank with water (enough for a 25% water change), an auto-doser that doses a dechlorinator solution (API), plus an airstone on a timer to mix it all for an hour, before emptying it (over 1.5 hours) via gravity into the tank on release of a low pressure solenoid, with waste water exiting via an overflow.

It all seems to work fairly well, but in the scheme of things is fairly complicated and has multiple points of possible failure such as the auto-doser not dosing correctly, or dosing insufficient dechlorinator, the header tank level valve failing and flooding, the inlet solenoid failing causing flow through of untreated tap water to the tank etc etc.

With that in mind, I note some users on this forum use HMA filters to remove chlorine, chloramine and heavy metals from the tap water for water changes, such as these units: https://www.devotedly-discus.co.uk/acatalog/DD-HMA-80.html#SID=26

This would work well for me, as I could simply have the HMA filter run straight into the tank, and eliminate my reliance reliance on the auto-doser, dechlorinator solution and the header tank and all its paraphernalia.

My concern is that on speaking to the sellers of these HMA filters, they cannot guarantee 100% removal of the Chlorine and Chloramine, and I don't want to cause any issues for the shrimp, fish and indeed the bacterial population of my tank.

That said, I also read on a number of threads, of quite experienced members of this forum not using dechlorinators at all for their fairly large weekly water changes, without apparent issue.

Question 1: So my first question is - am I worrying about nothing with regards to the small traces that might remain after HMA filtration? And therefore is the HMA filter a safe and valid replacement for my header tank system?

Question 2: My second question is on water changes in general. As I have an automated water change system, I can effectively do as many water changes as I like, without any increase in time or effort. I could theoretically do 12 x 25% changes every day if needed - though I'm sure that would be over-the-top and unnecessary.

I have read on other threads that there is no such thing as 'too many' water changes. So on that basis how many water changes might be optimum? I am EI dosing ferts too, so need to account for that to maintain sufficient concentrations.

I appreciate that is a little bit of a 'how long is a piece of string' question, and is dependent on a number of other variables, but I'd still like to know peoples thoughts in general.
 
I used to use HMA when I kept discus in an 800 litre system and coincidently I bought my HMA filter and discuss from Mark at Devotedly (I used to live in Sussex so they weren't too far aware)

In terms of removing Chlorine, etc, the HMA filter manufacturers are always going to caveat themselves however in reality he uses the same filters, so I wouldn't worry and certainly didn't. As you say, many people choose not to use dechlorinators on water changes anyway and coincidently I watched Cory @ Aquarium Coop discuss just this subject on You Tube last night (sorry I can't post a link as I'm at work and I can't access YouTube (IT police and all that!!) - if you want to find it and take a look it is his most recent video). At 25% water changes you will be absolutely fine as even if a trace amount of chlorine gets through it will be just that and then diluted out further by the volume of the tank

In terms of water changes, I'm no expert with EI dosing but I'm not sure how a drip water change would impact the 50% weekly water change 'reset' process on EI so can't comment too much there. My gut feeling though is that you'd want to do them more frequently (say 25% every 2 or 3 days )
 
Make it more reliable using a plc ?
https://www.ukaps.org/forum/threads/how-to-use-a-plc-to-control-your-fish-tank.42993/

The issue with not dechlorinating is, as many people have found out to their cost, is that water companies will often change the chlorine levels or add chlorine in during emergency works. Emergency works can be burst pipes, overloaded water processing plants and water pipe contamination. Aeration for 24 hours will get rid of chlorine, but not chloramine, which is why members have ended up wiping out their fish after a water change. Rory in his fish house lost over £650 of fish after chloramine was added to his water after water supply was contaminated after storms and he only prepped his water by 24 hours aeration.

HMA filters do fully remove chlorine/chloramine IF water is flowing slow enough AND they are not exhausted. One of my local fish shops showed me his equipment (ooh er missus) and they have massive HMA filters on their in coming water. They had a water meter monitoring the flow and had written in the filter what the water meter reading was to be when to change the filter. They also tested the water for free chlorine frequently, just in case of issues. Yes they had had issues someone managed to fit the HMA De-Chlor filter (special one for dechlorination) with it still in its poly shipping bag :banghead: . So was spotted by slow water flow rate and chlorine present in the water. :banghead:.
 
I'm intrigued, did the guy get any joy from the water company in the end?
 
Hi all,
ian_m said:
is that water companies will often change the chlorine levels or add chlorine in during emergency works.
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That would be the one that worried me, and partially why I'm a rain-water user. It was a while ago now, but there were a lot of issues with this in the <"winter of 2010">.

When I lived in Bath we had <"Asellus in our water supply at one point">, which was entertaining, but ended with Wessex Water dosing insecticide to remove them.

cheers Darrel
 
ian_m said:
Make it more reliable using a plc ?
https://www.ukaps.org/forum/threads/how-to-use-a-plc-to-control-your-fish-tank.42993/

The issue with not dechlorinating is, as many people have found out to their cost, is that water companies will often change the chlorine levels or add chlorine in during emergency works. Emergency works can be burst pipes, overloaded water processing plants and water pipe contamination. Aeration for 24 hours will get rid of chlorine, but not chloramine, which is why members have ended up wiping out their fish after a water change. Rory in his fish house lost over £650 of fish after chloramine was added to his water after water supply was contaminated after storms and he only prepped his water by 24 hours aeration.

HMA filters do fully remove chlorine/chloramine IF water is flowing slow enough AND they are not exhausted. One of my local fish shops showed me his equipment (ooh er missus) and they have massive HMA filters on their in coming water. They had a water meter monitoring the flow and had written in the filter what the water meter reading was to be when to change the filter. They also tested the water for free chlorine frequently, just in case of issues. Yes they had had issues someone managed to fit the HMA De-Chlor filter (special one for dechlorination) with it still in its poly shipping bag :banghead: . So was spotted by slow water flow rate and chlorine present in the water. :banghead:.
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Thank Ian - I don't want to go down the plc route, and I don't think that would eliminate solenoid, dosing pump or overflow issues.

With regards to the HMA filter, flow rate shouldn't be an issue, as I'd need to limit it to about half a litre per minute anyway, to ensure the overflow can cope - most seem rated for 2 litres per minute+, so I'd be increasing contact time with the filter by design. Filter exhaustion shouldn't be an issue either; even if I do a 25% water change a day, that's less than 5,500 litres a year, and I'd change the filters out annually by default.
 
dw1305 said:
Hi all,
If any-one is interested in the full Asellus story, it is still on the <"BCA forum"> at its new web address. cheers Darrel
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Not nice...I used to be a lifeguard whilst I was at college, and it was quite common to find Gammarus in the pool. It was an old Victorian baths and had a large cockroach population as well. One of the first jobs of the day was to fish out the roaches that had decided to go swimming.

A remember a member of the public complaining about the shrimp in the pool. I assured him that they were important bioindicators for water quality assessment and their presence was a good sign, and since they were dead that the chlorine was obviously doing its job, he wasn't impressed 😀
 
Having used Ro/Di units for 25 years now. I never would trust basically the first 3 stages of an RO unit which is what the HMA filter is. I have seen the water company change their treatment over night.
I just make a batch of water for a tank. Add what is needed to get the water correct for the Aqurium remove water and pump water in from the mixing tank.
 
I'm intrigued, did the guy get any joy from the water company in the end?
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No he got nothing back. The water company supplied water within regulations. In the end he gave up and broke down his "fish house" and all 22 tank, after having spent £1000's on it. 🙁

The ammonia he talks about is the breakdown products of chloramine, which is often emergency injected into water pipes when there is an issue with supply contamination. Chloramine does not gas off and is quite persistent in water, which is why it is used, and is very toxic to fish, invertebrates and filter flora/fauna. Chloramine will also attack reverse osmosis membranes, leaving ammonia in the RO water, which is why RO users must use decent pre-filters and even test their RO water before use.

Chloramine is easily broken down and removed using virtually any make of dechlorinator (even ultra cheap sodium thiosulphate) and most quality (de-chlor brand) water filters, making the water fish safe.
 
I'm assuming our tap water has Chloramine in it all the time anyway? So if I am slow trickling tap water through a HMA filter much slower than the rated max flow capacity, would that not remove any additional emergency chloramine added to the tap water also?

So I'd like to draw a conclusion under this - is a HMA filter used well under the max flow rate, with cartridges well within their useful life, safe for processing tap water for fish tanks or not?
 
Anyone want to venture some pointers on my second question in my OP?

I have initially been doing 3 x 25% water changes a week, but my TDS has gradually risen up to around 320ppm (tap water is 260ppm), so I've now increased the water changes to daily.

Water changes are done a couple of hours before lights on, and just before daily EI dosing. I'm guessing that 'should' be sufficient?
 
Hi all,
Wookii said:
but my TDS has gradually risen up to around 320ppm (tap water is 260ppm), so I've now increased the water changes to daily.
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That should be OK, just change enough water so that you don't get a continual rise in ppm TDS.
Wookii said:
I'm assuming our tap water has Chloramine in it all the time anyway?
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Usually it doesn't in the UK, but more water companies are using it, manly because the legislation on the maximum levels of faecal coliforms etc. is really tight.

In the USA they don't really have any consumer protection, or environmental, legislation so the water companies <"add a really large does of chlorine or chloramine">, mainly because it is cheaper than actually attempting to make the water safe and/or drinkable.

Chloramine tends to be used routinely only if water is likely to remain in the system for a long time before it reaches the consumer, or if it is likely that the integrity of the water main is suspect. The advantage of the chloramine for the water company is that it remains in solution a lot longer then chlorine gas does, that same persistence is also why it is such a problem in the tank.

You could ask "Severn-Trent Water" if they use chloramine, but they <"may be reluctant to tell you">.

cheers Darrel
 
dw1305 said:
That should be OK, just change enough water so that you don't get a continual rise in ppm TDS
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You could presumably also reduce fertiliser dosage, it may be this is contributing to the TDS rise. What are your nitrate levels like?
 
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