DeeTee Posted October 13, 2009 Report Share Posted October 13, 2009 I am totally confused now. After battling my new tank mysteriously turning acidic overnight for 3 weeks, and having checked/cleaned everything thoroughly, I tried it again with my platies and they all started surface gasping immediately. So I put them back in the old tank, and I got some inexpensive fish (x-ray tetras) and started again. They seemed fine for the first couple of days - and then, hey presto, surface gasping again. Water was also turning slightly cloudy. I was suspicious after reading all your comments that although there is a good water flow from my filtration system, it might not be causing adequate oxygenation, as it has an exit pipe below the waterline that points straight down into the tank, and the surface movement is negligable. I had bought a cheap airpump/airstone and quickly got that up and running and within 10 minutes all the gasping had stopped. Ran it for a couple of hours, turned it off, all well for a few hours - then sure enough, gasping again. Quickly resolved again when air had pump on for a few minutes. I've been running water tests every couple of days and now, guess what, the water is highly alkaline - at top of scale on my narrow range test kit (7.6). (My tap water is similar to this, but the tank water had previously been around 6. 8 ). I have not added any buffers/treatment agents other than a water conditioner/dechlorinator. I do have some "PH down" but 'm reluctant to rush around tinkering with my water willy nilly - any ideas as to what is happening? Is there a link between PH and oxygenation levels (or the lack of them)? PS: Fish seem active enough at present although haven't touched any of the flake food I've offered and I've had to try and remove it - they haven't eaten in 4 days ?? Quote Link to comment Share on other sites More sharing options...
phoenix44 Posted October 13, 2009 Report Share Posted October 13, 2009 keep your air pump on. there must always be movement on the water surface, that's how O2 diffuses into the water. Quote Link to comment Share on other sites More sharing options...
livingart Posted October 13, 2009 Report Share Posted October 13, 2009 and how some of the bad stuff escapes Quote Link to comment Share on other sites More sharing options...
Discusguru Posted October 14, 2009 Report Share Posted October 14, 2009 I think you worry too much. You'll have to create surface movement or keep the air pump on 24/7 so you don't stress the fish and yourself out. Once there is bio load in the tank the PH will drop. Give the tank time to settle and cycle. I wouldn't go and adjust the PH. It's not going to kill the fish. Quote Link to comment Share on other sites More sharing options...
wayneh Posted October 14, 2009 Report Share Posted October 14, 2009 What about the water hardness... This can effect the PH of the water, along with CO2. if your water is very soft and the co2 levels high the PH will swing. By the sounds of it, the air pump could be dispersing the co2 (via the surface agitation) as well as increasing the oxygen in the water.... Hence the PH swing... Not sure on the size of your tank, but must be fairly small if it only takes a couple of hours without air bubbles for the fish to gasp for air. I take it there are few or no plants either as they will add oxygen to the water also, given enough light... Quote Link to comment Share on other sites More sharing options...
DeeTee Posted October 14, 2009 Author Report Share Posted October 14, 2009 Thanks for all that - my tank is 100litres - so its not THAT small. No, I don't have much in the way of live plants at this stage. And yes, I am now running the air pump 24 hours. I will be checking my water hardness out of interest when I get a test kit (shop sold out last weekend) and I'm leaving my water alone at this stage! I've found an article that indicates PH rises with increased oxygenation due to higher levels of OH ions as opposed to H+ ions which make it more acidic. If thats the case all this acidity / alkalinity stuff has indeed probably been a red herring. The gasping fish and likely the initial ?toxic condition that developed after I left the tank fish-free for a few days (as indicated by a slight sulphurous smell and clouding) seems likely to have been due to one factor - poor oxygenation, and the PH fluctuations also secondary to that, and not of themselves all that important. Yes, I did get stressed outwhen my fish did - the rapid PH variation was the only potential cause I had at that stage. I'm learning. I intend to contact the manufacturers direct about the oxygen issue - surely I shouldn't have to be running the airpump fulltime - you don't expect to shell out for a supposedly complete new tank and end up with all these problems - or am I being naive???? Quote Link to comment Share on other sites More sharing options...
phoenix44 Posted October 14, 2009 Report Share Posted October 14, 2009 they are not H+ ions, but H30+ ions - the change in pH would be negligible. you do have to run a filter in a tank all the time - it creates water flow. an airpump usually also has to be on all the time if there is no water flow. It is in no way your tanks fault; or the manufacturers. Quote Link to comment Share on other sites More sharing options...
DeeTee Posted October 14, 2009 Author Report Share Posted October 14, 2009 I have been running the filter constantly - and was led to believe it was also sufficient to aerate the water - clearly this is not the case as unlike my other hang-on filters, this one doesn't create surface water movement. Quote Link to comment Share on other sites More sharing options...
phoenix44 Posted October 14, 2009 Report Share Posted October 14, 2009 what is the name/ brand and model of the filter? Quote Link to comment Share on other sites More sharing options...
Ira Posted October 14, 2009 Report Share Posted October 14, 2009 I have been running the filter constantly - and was led to believe it was also sufficient to aerate the water - clearly this is not the case as unlike my other hang-on filters, this one doesn't create surface water movement. Then make it so it does. Quote Link to comment Share on other sites More sharing options...
livingart Posted October 14, 2009 Report Share Posted October 14, 2009 a picture would help Quote Link to comment Share on other sites More sharing options...
Adrienne Posted October 14, 2009 Report Share Posted October 14, 2009 How many fish do you have in this tank? You really want to get to the bottom of why your water is changing so much. Do you only test pH or do you test for ammonia etc. Alkaline can be caused by high ammonia which may indicate your filter is not working properly or as you have said you cleaned everything thoroughly. Did you completely clean out your filter because if you do your tank could be cycling again and will take a while to settle. Low pH is not a problem unless you have some varieties of cichlids. Quote Link to comment Share on other sites More sharing options...
JazzyJeff Posted October 14, 2009 Report Share Posted October 14, 2009 So this is a canister filter? In my short lived experience... The water that is returning from the canister, is it dispersed thru a spray bar? If yes - check that the bar is more than an inch below the surface with the "holes" pointing at a 45 degree angle to the surface... If they are facing down they will not be creating surface movement. If no spray bar, perhaps you may need to get one? Mine came with bot a spray bar and a duck bill, I am assuming yours did too? Quote Link to comment Share on other sites More sharing options...
DeeTee Posted October 15, 2009 Author Report Share Posted October 15, 2009 Thanks for all the input. Here's where I have got to with it all: Rang the agents who handle these tanks and the canister filters that come with them (Blue Planet range). They advised me that the retailer had failed to provide me with some information that was on the packaging and a special leaflet (neither of which they claimed existed when I enquired). This would have told me that although the tank has a nice black framing top and bottom and appears to be one that you would be able to fill to the base of the 3-4cm black rim around the top of the tank - you can't. The canister is designed so that the outflow comes from underneath - there is no spray attachment available, and unless you have at least a 3-4 cm fall it fails to create the necessary surface agitation. So no surprises - my problem WAS poor oxygenation. Now I have the issue that the tank does NOT look very great with the water sitting below the framing like that (and it was supposed to be a feature in the living room) - something the suppliers generously acknowledged!! - AND as I grimly pointed out - judging by my measurements it won't be holding 100litres of water as claimed either. I shall be taking this up with them. Meantime, I am keeping the water level where it looks best, and employing an airstone to create the oxygenation. I would prefer not to have it, as the pump is noisy and it creates rather more agitation than I'd prefer - but its the lesser of evils at present, while I decide on my next move..... A case of caveat emptor, I guess. PS: As regards oxygenation influencing PH - I disagree that the impact is negible - an article I found noted that aerating 20litres of water for 4 hours changed PH from 7.8 to 8.6. Aerating my 100 litres overnight changed it from approx 6.6 - 6.8, up to 7.4. Of course water hardness would also be a factor in how much change occurred - I suspect my water is probably fairly soft. I'm not worried about the PH now because the 7.4 reflects my tapwater PH and more importantly its remaining stable since the airpump - it was the inexplicable rapid fluctuations that were worrying me (and the fish stress - which has also resolved). Quote Link to comment Share on other sites More sharing options...
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