DIY filter advice?

[Gandalf]

Need some advice from people who have done these filters before. I'm doing a plywood pond in my garage this week, either 6'x3'x2' or 8'x3'x2'. I've come across the idea many times of using a plastic tower drawer with 3-4 drawers for a filter, just pumping water through the top and letting it rain through the drawers. My questions are:

1. Can you do mechanical and biological together? My plan was to do 4 drawers, one full of filter floss, two more with a layer of filter floss, one with charcoal and the other with ammonia-remover, and the last one plastic pot scrubbers for biological. Is it okay to do this all together?

2. What is the max-flow rate they can usually take? I guess it depends on the size of what you get, but my pump will be doing 1200 gph, so can the filter take that?

3. If the pond is indoor, is a UV sterilizer needed? I know thats a stupid question since most fish tank filters have one, but is it really needed?

By the way, this pond is basically just for my silver arowana. I'm sure I'll add some other fish, but aro's need very clean water.

 

[wow_it_esploded]

1. Yes you can, it is reccomended so that your bio-media doesn't get all grungy. I would not worry about that much chemical though, esp the ammonia remover. The bio will take care of the ammonia, and the carbon should only be used to remove tannins or medication. I would do 1 drawer coarse mech, 1 drawer with finer mech on top of bio, and the 2 remaining drawers 100% bio.

2. It should definitely be able to handle that flow. Drill fewer holes than you think you want, and then run the system and keep adding holes until you get the perfect water distribution and flow-through.

3. UV Sterilizers are good for (1) green water, and (2) killing ich. Indoors, green water is probably not going to be an issue unless you have a lot of sunlight on the tank, but ich can still be a problem. For now, I would go without the UV and add it when funds come in at a later date, you'll be fine without it.

 

[Gandalf]

Thanks for the answers to my question. So should I not bother with the ammonia remover? I feel like I might as well do it anyways, just to be safe. How long does just bio take to cycle? I'm planning on filling the pond at least 20-30% with water-change-water from my already cycled 75 gallon, then slowly adding R-O. Would the cycle be shorter this way?

 

[wow_it_esploded]

I think that the ammonia remover would actually make it less safe. If it needs replacing or recharging or whatever, and you remove it but don't have time to head to the store or your shipment is late, it would probably cause a minicycle.

It'll take 3-6 weeks to cycle, depending on how much oxygen your bio is getting and the load that you are putting on it. Fishless cycles are important.

Using change-water is going to do next to nothing at all, most (99-100%) of the bacteria is on tank surfaces and media, NOT in the water column. However, gravel-gunk, filter-gunk, and filter media will GREATLY shorten the cycle. If you have no other fish in the 75 but the aro, if you move the fish and all the media over at the same time you should not even have an issue with cycling (same amt of bac w/ same amount of fish) because water volume doesn't mean anything to the cycle.

 

[Gandalf]

Can ammonia remover and carbon be placed in the same drawer?

 

[wow_it_esploded]

Yes, they'll be fine. (but you still shouldn't use ammonia remover )