Hi sheag35,

Just to dispel any disinformation - if you stop using the OA products at the end of a monthly cycle there should be no crash in water quality as the traditional bacteria have had a month to colonize the media (even if it is only mechanical).
However, it would be prudent to keep a close eye on levels and get straight back into regular water changes as soon as you can if you discontinue using OA.

As far as costings go, in a situation such as yours where you are running many tanks, the Pond Range of OA products can be used.
Health Treatment (H.T.) comes in a 1kg size which treats 2,500 litres,
BBAC treats the same,
General Treatment (G.T.) 1litre will do 20,000 litres in a pond or 10,000 litres in a tank (different stocking densities = different bioload)for one week (ie- 1,000l for 10wks).

H.T. EURO 35
BBAC EURO 24
G.T. EURO 35

Total Kit EURO 94 (RRP, prices may vary)


For example 1x 300l, 2x 200l, 3x 100l tanks treated as follows-

H.T. & BBAC
Start Up - 1000l
Monthly - 250l (ie 25% w/c)

So 1x H.T. and 1x BBAC will last this group of tanks for Start Up and 6 months of maintenance at 25% p/m.
Then 1x H.T. and 1x BBAC will last for 10 months maintenance.

G.T.
1x G.T. dosed weekly will last 10 weeks

2x H.T. EURO 70
2x BBAC EURO 48
6x G.T. EURO 210

EURO 328 = 16 months
EURO 20.5= 1 month (average)

Remember though that not only are you saving time and water but you are also not using any chemicals.

Hope this helps...

Cheers,

Steve

Steve,
Your maths are appealing for the bulk buy and given the reduction in the workload and water. I'm delighted with my setup. The tank looks spotless, the fish, snail and shrimp look very happy. the amano shrimp has even shred his skin and reappeared in his new coat. the plants are looking healthy and I get more time to spend looking rather than having to fill, heeat water etc and I have only one tank. I'm tempted to do the bulk purchase ven for my limited set up.
If I can find the right 'quiet' air pump my other small tank will also follow the same OA route

Feargal

PS: Would really like to talk to you re a marine OA tank as the sponsors have a very good offer at the moment but put off by having to do weekly water changes etc and getting the water parameters right each time. A monthly change would lessen the stree on ME and the fish

Nice one Feargal,

Glad to hear that all is still well.

In so far as setting up a salt water system, I would advise you to go for it!

As you know there is some discussion about this in the marine forum (converting a rio 180 to marine) at the moment but if you do choose to go down this road please contact me directly when doing so and I can give you step by step advise on getting started.

Cheers,

Steve

P.S. Use a valve to 'tune' your airflow. This will offer some back pressure to the airpump and quieten it down considerably. S